Firetext does not have a status code for temporary-failure.

In order to set a message as temporary-failure, we check if it is in pending status first.
Otherwise a delivery receipt for failure is set to permanent failure.

tests/conftest.py

@@ -40,6 +40,7 @@ def notify_db(notify_api, request):
     def teardown():
         db.session.remove()
         db.drop_all()
+        db.engine.execute("drop type notify_status_types")
         db.engine.execute("drop table alembic_version")
         db.get_engine(notify_api).dispose()