.github/workflows/checks.yml in pronto-rubocop-0.11.0 vs .github/workflows/checks.yml in pronto-rubocop-0.11.1

@@ -5,16 +5,28 @@
     branches: [ master ]
   pull_request:
     branches: [ master ]
 
 jobs:
-  ruby:
+  unit_tests:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        ruby: ['2.3', '2.4', '2.5', '2.6', '2.7', '3.0']
+        ruby: ['2.4', '2.5', '2.6', '2.7', '3.0']
+        rubocop: ['0.63.1', '0.81.0', '0.84.0', '0.85.0', '0.86.0', '0.87.0', '< 1.0', '1.0.0', '< 2.0']
+        include:
+          - ruby: '2.3'
+            rubocop: '0.63.1'
+          - ruby: '2.3'
+            rubocop: '0.81.0'
+      fail-fast: false
     steps:
     - uses: actions/checkout@v2
+    - name: use specific rubocop version
+      run: echo "gem 'rubocop', '${{ matrix.rubocop }}'" > Gemfile.local
+    - name: use specific rubocop-ast version (if required)
+      if: matrix.rubocop == '0.84.0' || matrix.rubocop == '0.85.0'
+      run: echo "gem 'rubocop-ast', '< 0.7.0'" >> Gemfile.local
     - uses: ruby/setup-ruby@v1
       with:
         ruby-version: ${{ matrix.ruby }}
         bundler-cache: true
     - name: rake spec