Add ruby 3.0 and 3.1 to the test matrix

.github/workflows/test.yml

@@ -22,15 +22,12 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        ruby-version: ['2.6', '2.7']
+        ruby-version: ['2.6', '2.7', '3.0', '3.1']
 
     steps:
     - uses: actions/checkout@v3
     - name: Set up Ruby
-    # To automatically get bug fixes and new Ruby versions for ruby/setup-ruby,
-    # change this to (see https://github.com/ruby/setup-ruby#versioning):
-    # uses: ruby/setup-ruby@v1
-      uses: ruby/setup-ruby@2b019609e2b0f1ea1a2bc8ca11cb82ab46ada124
+      uses: ruby/setup-ruby@v1
       with:
         ruby-version: ${{ matrix.ruby-version }}
         bundler-cache: true # runs 'bundle install' and caches installed gems automatically