title: South 'nothing to migrate' message after successful schema migration
body: <p>I have a Django app that I added South to, performed some migrations with, and runs as expected on my local machine. However, I have had nothing but database errors after pushing my project to Heroku.  </p>
  
  <p>In trying to deal with one database error I am experiencing, I attempted a test where I deleted one of my models, pushed the edited models file to Heroku and ran:</p>
  
  <pre><code>heroku run python manage.py schemamigration django_app test_remove_pub --auto
  </code></pre>
  
  <p>This seemed to work fine. I got back the message:</p>
  
  <pre><code>Running `python manage.py schemamigration apricot_app test_remove_pub --auto` attached   
  to terminal... up, run.6408
   - Deleted model django_app.Publication
   - Deleted M2M table for journalists on django_app.Publication
   - Deleted M2M table for tags on apricot_app.Publication
  Created 0006_test_remove_pub.py. You can now apply this migration with: ./manage.py   
  migrate django_app
  </code></pre>
  
  <p>So, South appeared to do everything I expected - it deleted my model and its many to many relationships and made the appropriate migration file. Next, I enter: </p>
  
  <pre><code> heroku run python manage.py migrate django_app
  </code></pre>
  
  <p>And I get back:</p>
  
  <pre><code>Running `python manage.py migrate django_app` attached to terminal... up, run.4792  
  Running migrations for django_app:
  - Nothing to migrate.
  - Loading initial data for django_app.
  Installed 0 object(s) from 0 fixture(s)
  </code></pre>
  
  <p>Why would it say "nothing to migrate" when obviously there are things to migrate??</p>