Move dependencies used at generation time only to dev dependencies

Gemfile

@@ -21,7 +21,6 @@ group :development do
   gem 'rmail', '~> 1.1'
   gem 'sinatra', '~> 1.4'
   gem 'redis', '~> 3.2'
-  gem 'activesupport', '>= 3.2', '< 5.0'
 end
 
 platforms :jruby do