Add GitHub Actions

Added GitHub Actions to test both the Docker and Podman code paths since
I was unable to get the Travis tests to work properly.

Author: trevor-vaughan

.github/workflows/unit_test.yml

@@ -0,0 +1,66 @@
+name: Unit Tests
+on:
+  push:
+    branches:
+      # A test branch for seeing if your tests will pass in your personal fork
+      - test_me_github
+  pull_request:
+    branches:
+      - main
+      - master
+jobs:
+  docker-rspec:
+    runs-on:
+      - ubuntu-latest
+    strategy:
+      matrix:
+        ruby:
+          - 2.7
+          - 2.6
+          - 2.5
+          - 2.4
+        docker_version:
+          - 5:19.03.8~3-0~ubuntu-bionic
+          - 5:18.09.9~3-0~ubuntu-bionic
+          - 18.06.3~ce~3-0~ubuntu
+      fail-fast: true
+    steps:
+      - uses: actions/checkout@v2
+      - uses: actions/setup-ruby@v1
+        with:
+          ruby-version: ${{ matrix.ruby }}
+      - name: install bundler
+        run: |
+          gem install bundler -v '~> 1.17.3'
+          bundle update
+      - name: install docker
+        env:
+          DOCKER_VERSION: ${{ matrix.docker_version }}
+        run: sudo ./script/install_docker.sh ${DOCKER_VERSION} ${DOCKER_CE}
+      - name: spec tests
+        run: bundle exec rake
+
+  podman-rspec:
+    runs-on:
+      - ubuntu-latest
+    strategy:
+      matrix:
+        ruby:
+          - 2.7
+          - 2.6
+          - 2.5
+          - 2.4
+      fail-fast: true
+    steps:
+      - uses: actions/checkout@v2
+      - uses: actions/setup-ruby@v1
+        with:
+          ruby-version: ${{ matrix.ruby }}
+      - name: install bundler
+        run: |
+          gem install bundler -v '~> 1.17.3'
+          bundle update
+      - name: install podman
+        run: sudo ./script/install_podman.sh
+      - name: spec tests
+        run: bundle exec rake

script/install_podman.sh

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+#!/bin/sh
+set -ex
+
+. /etc/os-release
+
+curl -L https://download.opensuse.org/repositories/devel:/kubic:/libcontainers:/stable/xUbuntu_${VERSION_ID}/Release.key | sudo apt-key add -
+
+echo "deb https://download.opensuse.org/repositories/devel:/kubic:/libcontainers:/stable/xUbuntu_18.04/ /" > /etc/apt/sources.list.d/podman.list
+
+apt-get update
+
+apt-get install -y podman