title: (Django) Create a management command that will override the default settings in BaseCommand
body: <p>We always run our tests off of settings_test, like so: ./manage.py test someapp --settings=settings_test. The problem is that it's sometimes problematic to remember to add the option. </p>
  
  <p>I'd like to introduce a common app that just has the management command test.py. Depending on it's placement in the INSTALLED_APPS setting, it will override the default. Inside the command itself, I'd like to change the default of the --settings option. How can I do that?</p>
  
  <p>I am aware that I can create a local.py file that is similar to manage.py but with settings_test instead of settings. However, the point is to still run ./manage.py, but with having settings_test as default instead of constantly typing "--settings=settings_test" after ./manage.py test someapp</p>