Add Rails 7.0 and Ruby 3.1 to build matrix
Add Rails 7.0 and Ruby 3.1 to build matrix

https://www.ruby-lang.org/en/news/2021/12/25/ruby-3-1-0-released/
https://rubyonrails.org/2021/12/15/Rails-7-fulfilling-a-vision

rspec/rspec-rails,rspec/rspec-rails,rspec/rspec-rails