.github/workflows/rake.yml in mimoco-0.2.0 vs .github/workflows/rake.yml in mimoco-0.3.0

@@ -11,10 +11,10 @@
       matrix:
 #        os: [ubuntu-latest, macos-latest]
         os: [ubuntu-latest]
         # Due to https://github.com/actions/runner/issues/849, we have to use quotes for '3.0'
 #        ruby: [2.5, 2.6, 2.7, '3.0', head, jruby, jruby-head, truffleruby, truffleruby-head]
-        ruby: ["3.0.3"]
+        ruby: ["2.7.2", "3.0.1", 3.1.0]
         test_command: ["bundle exec rake test"]
     runs-on: ${{ matrix.os }}
 
     steps:
     - uses: actions/checkout@v2