Extract EE specific files/lines for spec/features/projects

We have the following files containing EE specific code. We should move them to ee/

• spec/features/projects/branches_spec.rb
• spec/features/projects/members/share_with_group_and_members_spec.rb
• spec/features/projects/merge_requests/user_creates_merge_request_spec.rb

2 of the files have a lot of difference!