Add rubygem-cucumber-rails 1.7.0

Cucumber-Rails is a Rails generators for Cucumber with special support for
Capybara and DatabaseCleaner. It brings Cucumber to Rails 4.2 and Rails 5.x.
This gem is also compatible with Rails 6.0+ but this is currently in a beta
phase, so there may be issues.

WWW: https://github.com/cucumber/cucumber-rails