Desk updates, more output openscholar/openscholar#3168

Two changes:
1. When a github issue notifies desk, only notify open,pending,resolved issues.  New issues haven't been looked at and shouldn't have a gh id yet.  Closed issues shouldn't be notified.
2. Only check to notify milestone and state changes when milestone and state are not null.

Also added more output inside the loop that does the notifications.  That's where the problems are right now.