This reverts commit 3d2617983b.
The change was not quite right because the method six provides needs to
have `self` be passed in as well. See the docs here:
https://six.readthedocs.io/#unittest-assertions
Reverting for now and we can fix it in smaller chunks later.
Open EdX Features ----------------- This is the root package for Open edX features that extend the edX platform. The intention is that these features would ideally live in an external repository, but for now they live in edx-platform but are cleanly modularized.