Fix time-dependent test

This test would fail when the two timezones is covers landed on
different days (like in the first few hours of UTC). So let's fix the
test to a particular moment in time.

test/controllers/events_controller_test.rb

@@ -5,6 +5,7 @@ class EventsControllerTest < ActionDispatch::IntegrationTest
     sign_in_as :kevin
 
     events(:layout_assignment_jz).update!(created_at: Time.current.beginning_of_day + 8.hours)
+    travel_to Time.current.beginning_of_day + 15.hours
   end
 
   test "index" do