Update ruby.yml to include ruby 3.0, 2.7, 2.6 & 2.5

Author: Anil Kumar Maurya

.github/workflows/ruby.yml

@@ -17,16 +17,17 @@ jobs:
   test:
 
     runs-on: ubuntu-latest
+    
+    strategy:
+      matrix:
+        ruby-version: [3.0.x, 2.7.x, 2.6.x, 2.5.x]
 
     steps:
     - uses: actions/checkout@v2
-    - 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
+    - name: Set up Ruby ${{ matrix.ruby-version }}
       uses: ruby/setup-ruby@v1
       with:
-        ruby-version: 2.6
+        ruby-version: ${{ matrix.ruby-version }}
     - name: Install dependencies
       run: bundle install
     - name: Compile