Calling open() with mode 'w' or 'a' will create a file if it doesn't exist,
while mode 'r' will cause an exception. This can be easily tested with:
python -c 'open("test.tmp", "w")'
ls test.tmp
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)