ruby on rails - cannot load such file -- paypal/express on db migrate

Question

I have installed the paypal express gem and after trying to do migrations I receive a cannot load such file -- paypal/express error.

Log:

$ gem install paypal-express
Successfully installed paypal-express-0.5.5
Parsing documentation for paypal-express-0.5.5
1 gem installed
$ rake db:migrate
rake aborted!
cannot load such file -- paypal/express
/.rvm/gems/ruby-2.0.0-p353/gems/activesupport-4.0.0.rc1/lib/active_support/dependencies.rb:228:in `require'
/.rvm/gems/ruby-2.0.0-p353/gems/activesupport-4.0.0.rc1/lib/active_support/dependencies.rb:228:in `block in require'
/.rvm/gems/ruby-2.0.0-p353/gems/activesupport-4.0.0.rc1/lib/active_support/dependencies.rb:213:in `load_dependency'
/.rvm/gems/ruby-2.0.0-p353/gems/activesupport-4.0.0.rc1/lib/active_support/dependencies.rb:228:in `require'
/dating/config/initializers/paypal.rb:1:in `<top (required)>'
/.rvm/gems/ruby-2.0.0-p353/gems/activesupport-4.0.0.rc1/lib/active_support/dependencies.rb:222:in `load'
/.rvm/gems/ruby-2.0.0-p353/gems/activesupport-4.0.0.rc1/lib/active_support/dependencies.rb:222:in `block in load'
/.rvm/gems/ruby-2.0.0-p353/gems/activesupport-4.0.0.rc1/lib/active_support/dependencies.rb:213:in `load_dependency'
/.rvm/gems/ruby-2.0.0-p353/gems/activesupport-4.0.0.rc1/lib/active_support/dependencies.rb:222:in `load'
/.rvm/gems/ruby-2.0.0-p353/gems/railties-4.0.0.rc1/lib/rails/engine.rb:609:in `block (2 levels) in <class:Engine>'
/.rvm/gems/ruby-2.0.0-p353/gems/railties-4.0.0.rc1/lib/rails/engine.rb:608:in `each'
/.rvm/gems/ruby-2.0.0-p353/gems/railties-4.0.0.rc1/lib/rails/engine.rb:608:in `block in <class:Engine>'
/.rvm/gems/ruby-2.0.0-p353/gems/railties-4.0.0.rc1/lib/rails/initializable.rb:30:in `instance_exec'
/.rvm/gems/ruby-2.0.0-p353/gems/railties-4.0.0.rc1/lib/rails/initializable.rb:30:in `run'
/.rvm/gems/ruby-2.0.0-p353/gems/railties-4.0.0.rc1/lib/rails/initializable.rb:55:in `block in run_initializers'
/.rvm/gems/ruby-2.0.0-p353/gems/railties-4.0.0.rc1/lib/rails/initializable.rb:44:in `each'
/.rvm/gems/ruby-2.0.0-p353/gems/railties-4.0.0.rc1/lib/rails/initializable.rb:44:in `tsort_each_child'
/.rvm/gems/ruby-2.0.0-p353/gems/railties-4.0.0.rc1/lib/rails/initializable.rb:54:in `run_initializers'
/.rvm/gems/ruby-2.0.0-p353/gems/railties-4.0.0.rc1/lib/rails/application.rb:214:in `initialize!'
/.rvm/gems/ruby-2.0.0-p353/gems/railties-4.0.0.rc1/lib/rails/railtie/configurable.rb:30:in `method_missing'
/dating/config/environment.rb:5:in `<top (required)>'
/.rvm/gems/ruby-2.0.0-p353/gems/activesupport-4.0.0.rc1/lib/active_support/dependencies.rb:228:in `require'
/.rvm/gems/ruby-2.0.0-p353/gems/activesupport-4.0.0.rc1/lib/active_support/dependencies.rb:228:in `block in require'
/.rvm/gems/ruby-2.0.0-p353/gems/activesupport-4.0.0.rc1/lib/active_support/dependencies.rb:213:in `load_dependency'
/.rvm/gems/ruby-2.0.0-p353/gems/activesupport-4.0.0.rc1/lib/active_support/dependencies.rb:228:in `require'
/.rvm/gems/ruby-2.0.0-p353/gems/railties-4.0.0.rc1/lib/rails/application.rb:188:in `require_environment!'
/.rvm/gems/ruby-2.0.0-p353/gems/railties-4.0.0.rc1/lib/rails/application.rb:248:in `block in run_tasks_blocks'
/.rvm/gems/ruby-2.0.0-p353/bin/ruby_executable_hooks:15:in `eval'
/.rvm/gems/ruby-2.0.0-p353/bin/ruby_executable_hooks:15:in `<main>'
Tasks: TOP => db:migrate => environment

Answer 1

Put gem 'paypal-express' in your Gemfile and run bundle install. You shouldn't even have to require paypal/express in your initializer.