Remove time zone information from assertion in timeago tooltips spec

This allows the test to pass when your local time zone is different
than UTC.
"Date Format" JavaScript library uses a custom, non-standard format
when displaying time zone part of the datetime. There is no point in
trying to replicate this behavior in Ruby.

spec/features/dashboard/datetime_on_tooltips_spec.rb

@@ -6,7 +6,7 @@ feature 'Tooltips on .timeago dates', feature: true, js: true do
   let(:user)            { create(:user) }
   let(:project)         { create(:project, name: 'test', namespace: user.namespace) }
   let(:created_date)    { Date.yesterday.to_time }
-  let(:expected_format) { created_date.strftime('%b %-d, %Y %l:%M%P UTC') }
+  let(:expected_format) { created_date.strftime('%b %-d, %Y %l:%M%P') }
 
   context 'on the activity tab' do
     before do