How to automatically destroy django test database

Use --help to see the docs of the test command:

>>> ./manage.py test --help   
Usage: ./manage.py test [options] [appname ...]

Runs the test suite for the specified applications, or the entire site if no apps are specified.

[...]

--noinput             Tells Django to NOT prompt the user for input of any
                      kind.

And use --noinput which defaults to destroying the test db;)