This needs to be deployed to both staging and prod at the same
off-peak time (and the schema migration run).
At the time it is deployed, we need to make a few changes directly in
the database:
(1) UPDATE django_content_type set app_label='zerver' where app_label='zephyr';
(2) UPDATE south_migrationhistory set app_name='zerver' where app_name='zephyr';
(imported from commit eb3fd719571740189514ef0b884738cb30df1320)
When the backend is failing, the frontend often fails in much less
clear ways (e.g. timing out), so it's generally more useful to run the
backend tests first.
(imported from commit 36ac862ad1dbb21e32c0f44ba135c3c29bbea2f5)