collapse test jobs into a matrix configuration

Author: barmintor

.github/workflows/ci.yml

@@ -5,76 +5,24 @@ on:
     branches: [ '*' ]
 
 jobs:
-  test_rails_52:
-    runs-on: ubuntu-latest
-    strategy:
-      matrix:
-        ruby-version: ['2.2.10', '2.5.8', 'jruby-9.2.20.1']
-        gemfile:
-          - rails_52
-    env:
-      RAILS_ENV: test
-
-    steps:
-      - uses: actions/checkout@v2
-      - name: Add --no-document option to .gemrc file to speed up bundle install
-        run: "echo 'gem: --no-document' > ~/.gemrc"
-      - name: Set up Ruby
-        uses: ruby/setup-ruby@v1
-        with:
-          ruby-version: ${{ matrix.ruby-version }}
-          bundler-cache: true # runs 'bundle install' and caches installed gems automatically
-      - name: Run CI task
-        run: bundle exec rake
-  test_rails_60:
+  test_matrix:
     runs-on: ubuntu-latest
     strategy:
       matrix:
         ruby-version: ['2.5.8', '2.7.6', 'jruby-9.2.20.1']
         gemfile:
+          - rails_52
           - rails_60
-    env:
-      RAILS_ENV: test
-
-    steps:
-      - uses: actions/checkout@v2
-      - name: Add --no-document option to .gemrc file to speed up bundle install
-        run: "echo 'gem: --no-document' > ~/.gemrc"
-      - name: Set up Ruby
-        uses: ruby/setup-ruby@v1
-        with:
-          ruby-version: ${{ matrix.ruby-version }}
-          bundler-cache: true # runs 'bundle install' and caches installed gems automatically
-      - name: Run CI task
-        run: bundle exec rake
-  test_rails_61:
-    runs-on: ubuntu-latest
-    strategy:
-      matrix:
-        ruby-version: ['2.5.8', '2.7.6', 'jruby-9.2.20.1']
-        gemfile:
           - rails_61
-    env:
-      RAILS_ENV: test
+        include:
+          - ruby-version: 2.2.10
+            gemfile: rails_52
+          - ruby-version: 2.7.6
+            gemfile: rails_70
+        exclude:
+          - ruby-version: 2.7.6
+            gemfile: rails_52
 
-    steps:
-      - uses: actions/checkout@v2
-      - name: Add --no-document option to .gemrc file to speed up bundle install
-        run: "echo 'gem: --no-document' > ~/.gemrc"
-      - name: Set up Ruby
-        uses: ruby/setup-ruby@v1
-        with:
-          ruby-version: ${{ matrix.ruby-version }}
-          bundler-cache: true # runs 'bundle install' and caches installed gems automatically
-      - name: Run CI task
-        run: bundle exec rake
-  test_rails_70:
-    runs-on: ubuntu-latest
-    strategy:
-      matrix:
-        ruby-version: ['2.7.6']
-        gemfile:
-          - rails_70
     env:
       RAILS_ENV: test