Run the acceptance test with Rails 6.1

Author: rafaelfranca

CONTRIBUTING.md

@@ -30,7 +30,7 @@ acceptance tests again, which will generate a new app.
 You can set the `RAILS_VERSION` environment variable:
 
 ```
-$ RAILS_VERSION="~> 3.2.0" rake test:acceptance
+$ RAILS_VERSION="6.1" rake test:acceptance
 ```
 
 The apps in `test/apps` will be named based on the rails version, and the

Gemfile

@@ -6,5 +6,5 @@ gemspec
 if ENV["RAILS_VERSION"] == "edge"
   gem "activesupport", github: "rails/rails", branch: "main"
 elsif ENV["RAILS_VERSION"]
-  gem "activesupport", ENV["RAILS_VERSION"]
+  gem "activesupport", "~> #{ENV["RAILS_VERSION"] || "6.1"}.0"
 end

test/support/acceptance_test.rb

@@ -14,7 +14,7 @@ def rails_version
         if ENV['RAILS_VERSION'] == "edge"
           "7.0.0.alpha"
         else
-          '~> 6.0.0'
+          "~> #{ENV['RAILS_VERSION'] || "6.1"}.0"
         end
       end