title: Run migrations against the test database
body: <p>I do not want migrations to be run before each test round, that's why I run my tests with <code>--reusedb --nomigrations</code></p>
  
  <p>I still need to setup the database, once. For that I do:</p>
  
  <pre><code>python manage.py migrate
  </code></pre>
  
  <p>How do I tell <code>migrate</code> to run in "test" mode, so that the right databases (with the <code>test_</code> are used)?</p>