Move lib/gitlab dependency to application

We use the `Gitlab.ee` and `.ee?` methods in several initializers now.

config/application.rb

@@ -6,6 +6,7 @@ Bundler.require(:default, Rails.env)
 
 module Gitlab
   class Application < Rails::Application
+    require_dependency Rails.root.join('lib/gitlab')
     require_dependency Rails.root.join('lib/gitlab/redis/wrapper')
     require_dependency Rails.root.join('lib/gitlab/redis/cache')
     require_dependency Rails.root.join('lib/gitlab/redis/queues')

config/initializers/0_license.rb

-require_dependency 'lib/gitlab'
-
 Gitlab.ee do
   begin
     public_key_file = File.read(Rails.root.join(".license_encryption_key.pub"))