Explanation from IRC:

```
[16:20:41] <Hodgestar> So, the madness of auth / South / syncdb:
[16:20:57] <Hodgestar> * auth has two post_syncdb hooks.
[16:21:06] <Hodgestar> * tests use syncb even for things that use south.
[16:21:35] <Hodgestar> * our Travis tests test migrations by setting up the postgres database at the start
[16:22:09] <Hodgestar> * so for tests we need to have the syncdb hooks but for the test migration on Travis we can't.
```