Test against all of Ruby 3.x

Author: maedana

.github/workflows/test.yml

@@ -16,7 +16,7 @@ jobs:
       fail-fast: false
       matrix:
         os: ['ubuntu-18.04', 'ubuntu-latest', 'macos-latest']
-        ruby: ['2.6', '2.7']
+        ruby: ['2.6', '2.7', '3.0', '3.1']
         experimental: [false]
         include:
           - os: 'ubuntu-latest'

qiita-markdown.gemspec

@@ -26,7 +26,7 @@ Gem::Specification.new do |spec|
   spec.add_dependency "greenmat", "3.5.1.3"
   spec.add_dependency "sanitize"
   spec.add_dependency "addressable"
-  spec.add_development_dependency "activesupport", "4.2.6"
+  spec.add_development_dependency "activesupport", "~> 7.0.0"
   spec.add_development_dependency "benchmark-ips", "~> 1.2"
   spec.add_development_dependency "bundler"
   spec.add_development_dependency "codeclimate-test-reporter", "0.4.4"