Require Python 3.7 for start_tls support.

Support start_tls is required to allow proxying HTTPS connections,
since the unencrypted HTTP connection gets upgraded to HTTPS in-place
right after the CONNECT succeeds.

Remove 3.6 configurations for CI and such, add 3.8 where it was missing,
bump 3.8 images for CircleCI to the final ones.

.appveyor.yml

@@ -5,8 +5,8 @@ branches:
 skip_branch_with_pr: true
 
 environment:
-# websockets only works on Python >= 3.6.
-  CIBW_SKIP: cp27-* cp33-* cp34-* cp35-*
+# websockets only works on Python >= 3.7.
+  CIBW_SKIP: cp27-* cp33-* cp34-* cp35-* cp36-*
   CIBW_TEST_COMMAND: python -W default -m unittest
   WEBSOCKETS_TESTS_TIMEOUT_FACTOR: 100
 

.circleci/config.yml

@@ -11,15 +11,6 @@ jobs:
       - run: sudo pip install tox codecov
       - run: tox -e coverage,black,flake8,isort,mypy
       - run: codecov
-  py36:
-    docker:
-      - image: circleci/python:3.6
-    steps:
-      # Remove IPv6 entry for localhost in Circle CI containers because it doesn't work anyway.
-      - run: sudo cp /etc/hosts /tmp; sudo sed -i '/::1/d' /tmp/hosts; sudo cp /tmp/hosts /etc
-      - checkout
-      - run: sudo pip install tox
-      - run: tox -e py36
   py37:
     docker:
       - image: circleci/python:3.7
@@ -31,7 +22,7 @@ jobs:
       - run: tox -e py37
   py38:
     docker:
-      - image: circleci/python:3.8.0rc1
+      - image: circleci/python:3.8
     steps:
       # Remove IPv6 entry for localhost in Circle CI containers because it doesn't work anyway.
       - run: sudo cp /etc/hosts /tmp; sudo sed -i '/::1/d' /tmp/hosts; sudo cp /tmp/hosts /etc
@@ -44,9 +35,6 @@ workflows:
   build:
     jobs:
       - main
-      - py36:
-          requires:
-            - main
       - py37:
           requires:
             - main

.travis.yml

@@ -1,7 +1,7 @@
 env:
   global:
-  # websockets only works on Python >= 3.6.
-    - CIBW_SKIP="cp27-* cp33-* cp34-* cp35-*"
+  # websockets only works on Python >= 3.7.
+    - CIBW_SKIP="cp27-* cp33-* cp34-* cp35-*" cp36-*
     - CIBW_TEST_COMMAND="python3 -W default -m unittest"
     - WEBSOCKETS_TESTS_TIMEOUT_FACTOR=100
 

setup.cfg

@@ -1,5 +1,5 @@
 [bdist_wheel]
-python-tag = py36.py37
+python-tag = py37.py38
 
 [metadata]
 license_file = LICENSE

setup.py

@@ -21,8 +21,8 @@
 
 exec((root_dir / 'src' / 'websockets' / 'version.py').read_text(encoding='utf-8'))
 
-if sys.version_info[:3] < (3, 6, 1):
-    raise Exception("websockets requires Python >= 3.6.1.")
+if sys.version_info[:3] < (3, 7):
+    raise Exception("websockets requires Python >= 3.7.")
 
 packages = ['websockets', 'websockets/extensions']
 
@@ -51,7 +51,6 @@
         'Operating System :: OS Independent',
         'Programming Language :: Python',
         'Programming Language :: Python :: 3',
-        'Programming Language :: Python :: 3.6',
         'Programming Language :: Python :: 3.7',
         'Programming Language :: Python :: 3.8',
     ],
@@ -61,6 +60,6 @@
     ext_modules=ext_modules,
     include_package_data=True,
     zip_safe=False,
-    python_requires='>=3.6.1',
+    python_requires='>=3.7',
     test_loader='unittest:TestLoader',
 )

tox.ini

@@ -1,5 +1,5 @@
 [tox]
-envlist = py36,py37,py38,coverage,black,flake8,isort,mypy
+envlist = py37,py38,coverage,black,flake8,isort,mypy
 
 [testenv]
 commands = python -W default -m unittest {posargs}