Misc cleanups
Go at it slowly, commit per commit. I'm happy to split this in multiple pull requests if you prefer, just ask.
First commit removes the Django admin. We don't actually use it, so there's no need to load and expose it.
Second commit fixes #674 (closed).
And then, when I opened ideascube/tests/test_views.py
to remove the tests related to the Django admin, I found a few obvious issues. This prompted me to have a better look at the whole file, and I found quite a few more.
As such, all commits starting from the third one (in topological order) are for cleaning up and improving the tests in this file.