TEMP Switch to GitHub Actions for testing

.github/workflows/ruby.yml

@@ -0,0 +1,40 @@
+# This workflow uses actions that are not certified by GitHub.
+# They are provided by a third-party and are governed by
+# separate terms of service, privacy policy, and support
+# documentation.
+# This workflow will download a prebuilt Ruby version, install dependencies and run tests with Rake
+# For more information see: https://github.com/marketplace/actions/setup-ruby-jruby-and-truffleruby
+
+name: Ruby
+on: [push, pull_request]
+jobs:
+  test:
+    strategy:
+      fail-fast: false
+      matrix:
+        ruby:
+          - 2.7.0
+          - 2.6.5
+          - 2.5.7
+          - jruby-9.1.17.0
+        gemfile:
+          # These have webpacker:
+          - rails_5.2_no_sprockets
+          - rails_5.2_no_sprockets_webpacker_3
+          - rails_5.2_no_sprockets_webpacker_4
+          # These don't have webpacker:
+          - rails_5.2_sprockets_3
+          - rails_5.2_sprockets_4
+    runs-on: ubuntu-latest
+    env: # $BUNDLE_GEMFILE must be set at the job level, so it is set for all steps
+      BUNDLE_GEMFILE: ${{ github.workspace }}/gemfiles/${{ matrix.gemfile }}.gemfile
+    steps:
+    - uses: actions/checkout@v3
+    - uses: actions/setup-node@v3
+    - uses: ruby/setup-ruby@v1
+      with:
+        ruby-version: ${{ matrix.ruby }}
+        # TODO: Impalement caching
+        # bundler-cache: true
+    - run: bundle install
+    - run: bundle exec rake test