Remove explicit dependency on i18n

Depending on i18n's latest git version opens up opportunities to:
1. fail due to i18n's unstable changes
2. fail due to version conflict (their `master` can flip to 2.0, while `rails` would depend on `< 2`)

Rails explicitly depend on `i18n` anyway:
https://github.com/rails/rails/blob/c2b083df913f44e664576aafe24c41ec657f8eb5/activesupport/activesupport.gemspec#L36

Author: pirj

Gemfile-rails-dependencies

@@ -6,7 +6,6 @@ when /master/
   gem "activerecord-deprecated_finders", :git => "https://github.com/rails/activerecord-deprecated_finders.git"
   gem "web-console", :git => "https://github.com/rails/web-console", :group => :development
   gem 'coffee-rails', :git => "https://github.com/rails/coffee-rails.git"
-  gem 'i18n', :git => 'https://github.com/svenfuchs/i18n.git', :branch => 'master'
   gem 'sprockets', :git => 'https://github.com/rails/sprockets.git', :branch => 'master'
   gem 'sprockets-rails', :git => 'https://github.com/rails/sprockets-rails.git', :branch => 'master'
   gem 'puma', "3.12.1"