Test on ruby 3 as well

Author: deivid-rodriguez

.github/workflows/ci.yaml

@@ -23,7 +23,7 @@ jobs:
 
       - uses: ruby/setup-ruby@v1
         with:
-          ruby-version: 2.7.3
+          ruby-version: 3.0.1
           bundler-cache: true
 
       - name: Make sure gemfiles are up to date
@@ -50,10 +50,15 @@ jobs:
           - { name: ruby-2.5, value: 2.5.9 }
           - { name: ruby-2.6, value: 2.6.7 }
           - { name: ruby-2.7, value: 2.7.3 }
+          - { name: ruby-3.0, value: 3.0.1 }
           - { name: jruby-9.2, value: jruby-9.2.17.0 }
 
         rails: [rails_52, rails_60, rails_61]
 
+        exclude:
+          - ruby: { name: ruby-3.0, value: 3.0.1 }
+            rails: rails_52
+
     env:
       COVERAGE: true