Use the same Rubocop config fro CE and EE

Rémy Coutablerequested to merge
use-same-rubocop-config-for-ee into master

I'm currently reviewing the diff between CE and EE and found this.

The change in app/policies/project_policy.rb is needed to pass Rubocop's Metrics/AbcSize. I've choosen to use prepend since I find it elegant but I'm open to suggestion/feedback.

Merge request reports