South requirement is now fixed.
However, I'm not sure it's ok to have South as mandatory dependency, especially when Django 1.7 will be released.
If you're ok with that, I'll make another PR removing South (and mock) from setup.py
Both South and mock are not required for installing and using the package.
Removing them is not related to Django 1.7 support (they were optional all along) and
I wasn't sure you're +1 for this change after all. So I suggested making another pull-request. Is it ok?