Add rubocop to our build. (#5004)

lib/auth/current_user_provider.rb

@@ -12,12 +12,12 @@ class Auth::CurrentUserProvider
   end
 
   # log on a user and set cookies and session etc.
-  def log_on_user(user,session,cookies)
+  def log_on_user(user, session, cookies)
     raise NotImplementedError
   end
 
   # optional interface to be called to refresh cookies etc if needed
-  def refresh_session(user,session,cookies)
+  def refresh_session(user, session, cookies)
   end
 
   # api has special rights return true if api was detected
@@ -35,7 +35,6 @@ class Auth::CurrentUserProvider
     raise NotImplementedError
   end
 
-
   def log_off_user(session, cookies)
     raise NotImplementedError
   end