diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index be1382ad0..78719a57c 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -4,7 +4,7 @@ on:
   pull_request:
 
   push:
-    branches: [main, 0.1x]
+    branches: [main, 1.x, 0.1x]
 
 env:
   GIT_COMMIT_SHA: ${{ github.sha }}
@@ -14,9 +14,12 @@ env:
 jobs:
   linting:
     runs-on: ubuntu-latest
+    env:
+      BUNDLE_WITH: lint
+      BUNDLE_WITHOUT: development:test
 
     steps:
-    - uses: actions/checkout@v1
+    - uses: actions/checkout@v2
 
     - name: Set up Ruby 2.7
       uses: ruby/setup-ruby@v1
@@ -24,17 +27,10 @@ jobs:
         ruby-version: 2.7
 
     - name: Rubocop
-      run: |
-        gem install bundler
-        bundle config set without 'development test'
-        bundle config set with 'lint'
-        bundle install
-        bundle exec rubocop --format progress
+      run: bundle exec rubocop --format progress
 
     - name: Yard-Junk
-      run: |
-        gem install yard-junk --no-document
-        yard-junk --path lib
+      run: bundle exec yard-junk --path lib
 
   build:
     needs: [linting]
@@ -43,22 +39,14 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        ruby: ['2.4', '2.5', '2.6', '2.7', '3.0']
+        ruby: ['2.6', '2.7', '3.0']
 
     steps:
-    - uses: actions/checkout@v1
+    - uses: actions/checkout@v2
     - uses: ruby/setup-ruby@v1
       with:
         ruby-version: ${{ matrix.ruby }}
-
-    - name: Install dependencies
-      run: |
-        sudo apt-get install libcurl4-openssl-dev
-
-    - name: Build
-      run: |
-        gem install bundler -v '<2'
-        bundle install --jobs 4 --retry 3
+        bundler-cache: true
 
     - name: Test
       continue-on-error: ${{ matrix.experimental }}
diff --git a/.github/workflows/publish.yml b/.github/workflows/publish.yml
index 993dd06b3..e86f8cc9f 100644
--- a/.github/workflows/publish.yml
+++ b/.github/workflows/publish.yml
@@ -10,20 +10,14 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-      - uses: actions/checkout@master
+      - uses: actions/checkout@v2
 
-      - name: Set up Ruby 2.6
+      - name: Set up Ruby 2.7
         uses: actions/setup-ruby@v1
         with:
-          ruby-version: 2.6.x
+          ruby-version: 2.7
 
       - name: Publish to RubyGems
-        run: |
-          mkdir -p $HOME/.gem
-          touch $HOME/.gem/credentials
-          chmod 0600 $HOME/.gem/credentials
-          printf -- "---\n:rubygems_api_key: ${GEM_HOST_API_KEY}\n" > $HOME/.gem/credentials
-          gem build faraday.gemspec
-          gem push faraday-*.gem
-        env:
-          GEM_HOST_API_KEY: ${{ secrets.RUBYGEMS_AUTH_TOKEN }}
+        uses: dawidd6/action-publish-gem@v1
+        with:
+          api_key: ${{secrets.RUBYGEMS_AUTH_TOKEN}}
diff --git a/Gemfile b/Gemfile
index 66c9d29f4..1cad39848 100644
--- a/Gemfile
+++ b/Gemfile
@@ -2,39 +2,28 @@
 
 source 'https://rubygems.org'
 
-ruby RUBY_VERSION
-
+# Even though we don't officially support JRuby, this dependency makes Faraday
+# compatible with it, so we're leaving it in for jruby users to use it.
 gem 'jruby-openssl', '~> 0.10.7', platforms: :jruby
 
 group :development, :test do
+  gem 'coveralls_reborn', require: false
+  gem 'multipart-parser'
   gem 'pry'
+  gem 'rack', '~> 2.2'
   gem 'rake'
+  gem 'rspec', '~> 3.7'
+  gem 'rspec_junit_formatter', '~> 0.4'
+  gem 'simplecov'
+  gem 'webmock', '~> 3.4'
 end
 
-group :lint, :development do
+group :development, :lint do
   gem 'rubocop', '~> 0.90.0'
   gem 'rubocop-inclusivity', '~> 1.0'
   gem 'rubocop-packaging', '~> 0.5'
   gem 'rubocop-performance', '~> 1.0'
-end
-
-group :test, :development do
-  gem 'coveralls_reborn', require: false
-  gem 'em-http-request', '>= 1.1', require: 'em-http', platform: :ruby
-  gem 'em-synchrony', '>= 1.0.3', require: %w[em-synchrony em-synchrony/em-http], platform: :ruby
-  gem 'excon', '>= 0.27.4'
-  gem 'httpclient', '>= 2.2'
-  gem 'multipart-parser'
-  # TODO: remove this once v4 is released
-  options = (RUBY_VERSION.start_with?('3') ? { github: 'grosser/net-http-persistent', branch: 'grosser/spec' } : {})
-  gem 'net-http-persistent', '>= 3.0', **options
-  gem 'patron', '>= 0.4.2', platforms: :ruby
-  gem 'rack-test', '>= 0.6', require: 'rack/test'
-  gem 'rspec', '~> 3.7'
-  gem 'rspec_junit_formatter', '~> 0.4'
-  gem 'simplecov'
-  gem 'typhoeus', '~> 1.4'
-  gem 'webmock', '~> 3.4'
+  gem 'yard-junk'
 end
 
 gemspec
diff --git a/README.md b/README.md
index 2eca7371a..b8372cb73 100644
--- a/README.md
+++ b/README.md
@@ -16,10 +16,10 @@ Need more details? See the [Faraday API Documentation][apidoc] to see how it wor
 
 ## Supported Ruby versions
 
-This library aims to support and is [tested against][actions] the following Ruby
-implementations:
-
-* Ruby 2.4+
+This library aims to support and is [tested against][actions] the currently officially supported Ruby
+implementations. This means that, even without a major release, we could add or drop support for Ruby versions,
+following their [EOL](https://endoflife.date/ruby).
+Currently that means we support Ruby 2.6+
 
 If something doesn't work on one of these Ruby versions, it's a bug.
 
diff --git a/spec/faraday/adapter/em_http_spec.rb b/spec/faraday/adapter/em_http_spec.rb
deleted file mode 100644
index 721bd8251..000000000
--- a/spec/faraday/adapter/em_http_spec.rb
+++ /dev/null
@@ -1,49 +0,0 @@
-# frozen_string_literal: true
-
-unless defined?(JRUBY_VERSION)
-  RSpec.describe Faraday::Adapter::EMHttp do
-    features :request_body_on_query_methods, :reason_phrase_parse, :trace_method,
-             :skip_response_body_on_head, :parallel, :local_socket_binding
-
-    it_behaves_like 'an adapter'
-
-    it 'allows to provide adapter specific configs' do
-      url = URI('https://example.com:1234')
-      adapter = described_class.new nil, inactivity_timeout: 20
-      req = adapter.create_request(url: url, request: {})
-
-      expect(req.connopts.inactivity_timeout).to eq(20)
-    end
-
-    context 'Options' do
-      let(:request) { Faraday::RequestOptions.new }
-      let(:env) { { request: request } }
-      let(:options) { {} }
-      let(:adapter) { Faraday::Adapter::EMHttp.new }
-
-      it 'configures timeout' do
-        request.timeout = 5
-        adapter.configure_timeout(options, env)
-        expect(options[:inactivity_timeout]).to eq(5)
-        expect(options[:connect_timeout]).to eq(5)
-      end
-
-      it 'configures timeout and open_timeout' do
-        request.timeout = 5
-        request.open_timeout = 1
-        adapter.configure_timeout(options, env)
-        expect(options[:inactivity_timeout]).to eq(5)
-        expect(options[:connect_timeout]).to eq(1)
-      end
-
-      it 'configures all timeout settings' do
-        request.timeout = 5
-        request.read_timeout = 3
-        request.open_timeout = 1
-        adapter.configure_timeout(options, env)
-        expect(options[:inactivity_timeout]).to eq(3)
-        expect(options[:connect_timeout]).to eq(1)
-      end
-    end
-  end
-end
diff --git a/spec/faraday/adapter/em_synchrony_spec.rb b/spec/faraday/adapter/em_synchrony_spec.rb
deleted file mode 100644
index ce29e7186..000000000
--- a/spec/faraday/adapter/em_synchrony_spec.rb
+++ /dev/null
@@ -1,18 +0,0 @@
-# frozen_string_literal: true
-
-unless defined?(JRUBY_VERSION)
-  RSpec.describe Faraday::Adapter::EMSynchrony do
-    features :request_body_on_query_methods, :reason_phrase_parse,
-             :skip_response_body_on_head, :parallel, :local_socket_binding
-
-    it_behaves_like 'an adapter'
-
-    it 'allows to provide adapter specific configs' do
-      url = URI('https://example.com:1234')
-      adapter = described_class.new nil, inactivity_timeout: 20
-      req = adapter.create_request(url: url, request: {})
-
-      expect(req.connopts.inactivity_timeout).to eq(20)
-    end
-  end
-end
diff --git a/spec/faraday/adapter/excon_spec.rb b/spec/faraday/adapter/excon_spec.rb
deleted file mode 100644
index d80abc376..000000000
--- a/spec/faraday/adapter/excon_spec.rb
+++ /dev/null
@@ -1,49 +0,0 @@
-# frozen_string_literal: true
-
-RSpec.describe Faraday::Adapter::Excon do
-  features :request_body_on_query_methods, :reason_phrase_parse, :trace_method
-
-  it_behaves_like 'an adapter'
-
-  it 'allows to provide adapter specific configs' do
-    url = URI('https://example.com:1234')
-
-    adapter = described_class.new(nil, debug_request: true)
-
-    conn = adapter.build_connection(url: url)
-
-    expect(conn.data[:debug_request]).to be_truthy
-  end
-
-  context 'config' do
-    let(:adapter) { Faraday::Adapter::Excon.new }
-    let(:request) { Faraday::RequestOptions.new }
-    let(:uri) { URI.parse('https://example.com') }
-    let(:env) { { request: request, url: uri } }
-
-    it 'sets timeout' do
-      request.timeout = 5
-      options = adapter.send(:opts_from_env, env)
-      expect(options[:read_timeout]).to eq(5)
-      expect(options[:write_timeout]).to eq(5)
-      expect(options[:connect_timeout]).to eq(5)
-    end
-
-    it 'sets timeout and open_timeout' do
-      request.timeout = 5
-      request.open_timeout = 3
-      options = adapter.send(:opts_from_env, env)
-      expect(options[:read_timeout]).to eq(5)
-      expect(options[:write_timeout]).to eq(5)
-      expect(options[:connect_timeout]).to eq(3)
-    end
-
-    it 'sets open_timeout' do
-      request.open_timeout = 3
-      options = adapter.send(:opts_from_env, env)
-      expect(options[:read_timeout]).to eq(nil)
-      expect(options[:write_timeout]).to eq(nil)
-      expect(options[:connect_timeout]).to eq(3)
-    end
-  end
-end
diff --git a/spec/faraday/adapter/httpclient_spec.rb b/spec/faraday/adapter/httpclient_spec.rb
deleted file mode 100644
index 3cbf2c624..000000000
--- a/spec/faraday/adapter/httpclient_spec.rb
+++ /dev/null
@@ -1,73 +0,0 @@
-# frozen_string_literal: true
-
-RSpec.describe Faraday::Adapter::HTTPClient do
-  # ruby gem defaults for testing purposes
-  HTTPCLIENT_OPEN = 60
-  HTTPCLIENT_READ = 60
-  HTTPCLIENT_WRITE = 120
-
-  features :request_body_on_query_methods, :reason_phrase_parse, :compression,
-           :trace_method, :local_socket_binding
-
-  it_behaves_like 'an adapter'
-
-  it 'allows to provide adapter specific configs' do
-    adapter = described_class.new do |client|
-      client.keep_alive_timeout = 20
-      client.ssl_config.timeout = 25
-    end
-
-    client = adapter.build_connection(url: URI.parse('https://example.com'))
-    expect(client.keep_alive_timeout).to eq(20)
-    expect(client.ssl_config.timeout).to eq(25)
-  end
-
-  context 'Options' do
-    let(:request) { Faraday::RequestOptions.new }
-    let(:env) { { request: request } }
-    let(:options) { {} }
-    let(:adapter) { Faraday::Adapter::HTTPClient.new }
-    let(:client) { adapter.connection(url: URI.parse('https://example.com')) }
-
-    it 'configures timeout' do
-      assert_default_timeouts!
-
-      request.timeout = 5
-      adapter.configure_timeouts(client, request)
-
-      expect(client.connect_timeout).to eq(5)
-      expect(client.send_timeout).to eq(5)
-      expect(client.receive_timeout).to eq(5)
-    end
-
-    it 'configures open timeout' do
-      assert_default_timeouts!
-
-      request.open_timeout = 1
-      adapter.configure_timeouts(client, request)
-
-      expect(client.connect_timeout).to eq(1)
-      expect(client.send_timeout).to eq(HTTPCLIENT_WRITE)
-      expect(client.receive_timeout).to eq(HTTPCLIENT_READ)
-    end
-
-    it 'configures multiple timeouts' do
-      assert_default_timeouts!
-
-      request.open_timeout = 1
-      request.write_timeout = 10
-      request.read_timeout = 5
-      adapter.configure_timeouts(client, request)
-
-      expect(client.connect_timeout).to eq(1)
-      expect(client.send_timeout).to eq(10)
-      expect(client.receive_timeout).to eq(5)
-    end
-
-    def assert_default_timeouts!
-      expect(client.connect_timeout).to eq(HTTPCLIENT_OPEN)
-      expect(client.send_timeout).to eq(HTTPCLIENT_WRITE)
-      expect(client.receive_timeout).to eq(HTTPCLIENT_READ)
-    end
-  end
-end
diff --git a/spec/faraday/adapter/net_http_spec.rb b/spec/faraday/adapter/net_http_spec.rb
index fda9b64d5..01f3c807e 100644
--- a/spec/faraday/adapter/net_http_spec.rb
+++ b/spec/faraday/adapter/net_http_spec.rb
@@ -1,64 +1,9 @@
 # frozen_string_literal: true
 
+# Even though Faraday::Adapter::NetHttp is not shipped with Faraday anymore,
+# this is still useful to test `it_behaves_like 'an adapter'` shared examples.
 RSpec.describe Faraday::Adapter::NetHttp do
   features :request_body_on_query_methods, :reason_phrase_parse, :compression, :streaming, :trace_method
 
   it_behaves_like 'an adapter'
-
-  context 'checking http' do
-    let(:url) { URI('http://example.com') }
-    let(:adapter) { described_class.new }
-    let(:http) { adapter.send(:connection, url: url, request: {}) }
-
-    it { expect(http.port).to eq(80) }
-
-    it 'sets max_retries to 0' do
-      adapter.send(:configure_request, http, {})
-
-      expect(http.max_retries).to eq(0) if http.respond_to?(:max_retries=)
-    end
-
-    it 'supports write_timeout' do
-      adapter.send(:configure_request, http, write_timeout: 10)
-
-      expect(http.write_timeout).to eq(10) if http.respond_to?(:write_timeout=)
-    end
-
-    it 'supports open_timeout' do
-      adapter.send(:configure_request, http, open_timeout: 10)
-
-      expect(http.open_timeout).to eq(10)
-    end
-
-    it 'supports read_timeout' do
-      adapter.send(:configure_request, http, read_timeout: 10)
-
-      expect(http.read_timeout).to eq(10)
-    end
-
-    context 'with https url' do
-      let(:url) { URI('https://example.com') }
-
-      it { expect(http.port).to eq(443) }
-    end
-
-    context 'with http url including port' do
-      let(:url) { URI('https://example.com:1234') }
-
-      it { expect(http.port).to eq(1234) }
-    end
-
-    context 'with custom adapter config' do
-      let(:adapter) do
-        described_class.new do |http|
-          http.continue_timeout = 123
-        end
-      end
-
-      it do
-        adapter.send(:configure_request, http, {})
-        expect(http.continue_timeout).to eq(123)
-      end
-    end
-  end
 end
diff --git a/spec/faraday/adapter/patron_spec.rb b/spec/faraday/adapter/patron_spec.rb
deleted file mode 100644
index 2408ab044..000000000
--- a/spec/faraday/adapter/patron_spec.rb
+++ /dev/null
@@ -1,18 +0,0 @@
-# frozen_string_literal: true
-
-RSpec.describe Faraday::Adapter::Patron, unless: defined?(JRUBY_VERSION) do
-  features :reason_phrase_parse
-
-  it_behaves_like 'an adapter'
-
-  it 'allows to provide adapter specific configs' do
-    conn = Faraday.new do |f|
-      f.adapter :patron do |session|
-        session.max_redirects = 10
-        raise 'Configuration block called'
-      end
-    end
-
-    expect { conn.get('/') }.to raise_error(RuntimeError, 'Configuration block called')
-  end
-end
diff --git a/spec/faraday/adapter/rack_spec.rb b/spec/faraday/adapter/rack_spec.rb
deleted file mode 100644
index 4fe6cba28..000000000
--- a/spec/faraday/adapter/rack_spec.rb
+++ /dev/null
@@ -1,8 +0,0 @@
-# frozen_string_literal: true
-
-RSpec.describe Faraday::Adapter::Rack do
-  features :request_body_on_query_methods, :trace_method,
-           :skip_response_body_on_head
-
-  it_behaves_like 'an adapter', adapter_options: WebmockRackApp.new
-end
diff --git a/spec/faraday/adapter/typhoeus_spec.rb b/spec/faraday/adapter/typhoeus_spec.rb
deleted file mode 100644
index 7f63f9700..000000000
--- a/spec/faraday/adapter/typhoeus_spec.rb
+++ /dev/null
@@ -1,7 +0,0 @@
-# frozen_string_literal: true
-
-RSpec.describe Faraday::Adapter::Typhoeus do
-  features :request_body_on_query_methods, :parallel, :trace_method
-
-  it_behaves_like 'an adapter'
-end
diff --git a/spec/support/webmock_rack_app.rb b/spec/support/webmock_rack_app.rb
deleted file mode 100644
index a3212c71c..000000000
--- a/spec/support/webmock_rack_app.rb
+++ /dev/null
@@ -1,68 +0,0 @@
-# frozen_string_literal: true
-
-# Rack app used to test the Rack adapter.
-# Uses Webmock to check if requests are registered, in which case it returns
-# the registered response.
-class WebmockRackApp
-  def call(env)
-    req_signature = WebMock::RequestSignature.new(
-      req_method(env),
-      req_uri(env),
-      body: req_body(env),
-      headers: req_headers(env)
-    )
-
-    WebMock::RequestRegistry
-      .instance
-      .requested_signatures
-      .put(req_signature)
-
-    process_response(req_signature)
-  end
-
-  def req_method(env)
-    env['REQUEST_METHOD'].downcase.to_sym
-  end
-
-  def req_uri(env)
-    scheme = env['rack.url_scheme']
-    host = env['SERVER_NAME']
-    port = env['SERVER_PORT']
-    path = env['PATH_INFO']
-    query = env['QUERY_STRING']
-
-    url = +"#{scheme}://#{host}:#{port}#{path}"
-    url += "?#{query}" if query
-
-    uri = WebMock::Util::URI.heuristic_parse(url)
-    uri.path = uri.normalized_path.gsub('[^:]//', '/')
-    uri
-  end
-
-  def req_headers(env)
-    http_headers = env.select { |k, _| k.start_with?('HTTP_') }
-                      .map { |k, v| [k[5..-1], v] }
-                      .to_h
-
-    special_headers = Faraday::Adapter::Rack::SPECIAL_HEADERS
-    http_headers.merge(env.select { |k, _| special_headers.include?(k) })
-  end
-
-  def req_body(env)
-    env['rack.input'].read
-  end
-
-  def process_response(req_signature)
-    res = WebMock::StubRegistry.instance.response_for_request(req_signature)
-
-    if res.nil? && req_signature.uri.host == 'localhost'
-      raise Faraday::ConnectionFailed, 'Trying to connect to localhost'
-    end
-
-    raise WebMock::NetConnectNotAllowedError, req_signature unless res
-
-    raise Faraday::TimeoutError if res.should_timeout
-
-    [res.status[0], res.headers || {}, [res.body || '']]
-  end
-end