Add ruby 3.0 in GH Actions

Author: ericproulx

.github/workflows/test.yml

@@ -28,6 +28,7 @@ jobs:
           - 2.5
           - 2.6
           - 2.7
+          - 3.0
         gemfile:
           - Gemfile
           - gemfiles/rack1.gemfile
@@ -36,8 +37,15 @@ jobs:
           - gemfiles/rails_edge.gemfile
           - gemfiles/rails_5.gemfile
           - gemfiles/rails_6.gemfile
+          - gemfiles/rails_6_1.gemfile
         experimental: [false]
         include:
+          - ruby: 3.0
+            gemfile: 'gemfiles/multi_json.gemfile'
+            experimental: false
+          - ruby: 3.0
+            gemfile: 'gemfiles/multi_xml.gemfile'
+            experimental: false
           - ruby: 2.7
             gemfile: 'gemfiles/multi_json.gemfile'
             experimental: false