Wait for notifications to be dispatched

[jdmcd]

Fixes a race condition where a job could be marked as "running" in your notification consumer while it had actually succeeded.

Note: If you don't have any notification delegates registered this release will have no performance impact. If you are using notification delegates the dispatch function will now wait until all notifications have been sent to return.

[0xTim]

LGTM - I don't suppose there's a way to test this?

[jdmcd]

@0xTim not that I can think of, unfortunately. Since the race condition only pops up if there are speed problems with the database or a super fast job

[VaporBot]

These changes are now available in 1.5.2