FEATURE: Unconditionally notify on edits at least once a day

This ensures that at a minimum you are notified once a day of
repeat edits by the same user.

Long term we may consider winding this down to say 1 hour or
making it configurable.

app/services/post_alerter.rb

@@ -256,6 +256,7 @@ class PostAlerter
   end
 
   def should_notify_edit?(notification, post, opts)
+    notification.created_at < 1.day.ago ||
     notification.data_hash["display_username"] != (opts[:display_username].presence || post.user.username)
   end
 

spec/services/post_alerter_spec.rb

@@ -122,12 +122,16 @@ describe PostAlerter do
       freeze_time 2.hours.from_now
       post.revise(admin, raw: 'I made another revision')
 
+      # this we do not skip cause 1 day has passed
+      freeze_time 23.hours.from_now
+      post.revise(admin, raw: 'I made another revision xyz')
+
       post.revise(Fabricate(:admin), raw: 'I made a revision')
 
       freeze_time 2.hours.from_now
       post.revise(admin, raw: 'I made another revision')
 
-      expect(Notification.where(post_number: 1, topic_id: post.topic_id).count).to eq(4)
+      expect(Notification.where(post_number: 1, topic_id: post.topic_id).count).to eq(5)
     end
 
     it 'notifies flaggers when flagged post gets unhidden by edit' do