Fix/include coverage

![puppies](https://gs1.wac.edgecastcdn.net/8019B6/data.tumblr.com/ac3d27bdfdd27511adfaf86db335626f/tumblr_n1r1vdwEtJ1qdlh1io1_400.gif)

* Tox now gives coverage reports in the terminal.
* Tox now tests against Django 1.7 with Python 2.7.
* Tox now tests against Django 1.7 with Python 3.3.
* Tox uses the `.coveragerc` file to control how coverage runs.
* `setup.cfg` included so we can generate universal wheels.