Use ruby/setup-ruby for the Ruby starter workflow

ci/ruby.yml

@@ -1,3 +1,10 @@
+# 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:
@@ -7,18 +14,17 @@ on:
     branches: [ master ]
 
 jobs:
-  build:
+  test:
 
     runs-on: ubuntu-latest
 
     steps:
     - uses: actions/checkout@v2
-    - name: Set up Ruby 2.6
-      uses: actions/setup-ruby@v1
+    - name: Set up Ruby
+      uses: ruby/setup-ruby@v1
       with:
-        ruby-version: 2.6.x
-    - name: Build and test with Rake
-      run: |
-        gem install bundler
-        bundle install --jobs 4 --retry 3
-        bundle exec rake
+        ruby-version: 2.6
+    - name: Install dependencies
+      run: bundle install
+    - name: Run tests
+      run: bundle exec rake