Current behavior for both old and new exams paths on exam creation is
that the signal fires, the update code kicks off a celery task which
looks for a new exam, and that exam is not found so no actual update
is done. Or the old version is visible but the updated version is not.
By waiting until the change is actually committed, we should find the
new exam when we search for it.
This is currently an invisible bug just because of the large numbers
of updates that working on a course provides, the exam will be correct
unless it was the absolute last thing that was touched, in which case
it will be out of date.
0b68c84286