Django 1.8 disallows access to args[]

https://docs.djangoproject.com/en/1.8/howto/custom-management-commands/
You need to declare and do proper argument parsing.  --commit is also
more natural than a bare 'commit' on the end of a command.

Switch from calling handle() directly to call_command().
call_command() simulates using the management command so is a better
test of the command line interface.