Optimize notification emails specs

spec/support/notify_shared_examples.rb

 shared_context 'gitlab email notification' do
+  set(:project) { create(:project, :repository) }
+  set(:recipient) { create(:user, email: 'recipient@example.com') }
+
   let(:gitlab_sender_display_name) { Gitlab.config.gitlab.email_display_name }
   let(:gitlab_sender) { Gitlab.config.gitlab.email_from }
   let(:gitlab_sender_reply_to) { Gitlab.config.gitlab.email_reply_to }
-  let(:recipient) { create(:user, email: 'recipient@example.com') }
-  let(:project) { create(:project) }
   let(:new_user_address) { 'newguy@example.com' }
 
   before do