Registration tests broken with regards to 'upgrades'

One-sentence description

The upgrade tests are broken due to poor date handling.

Current behaviour

Broken build.

Expected behaviour

Build works.

Steps to reproduce

1. ./manage.py test

Suggested solution

Instead of mocking dates which is horribly complicated, use freezegun to fix dates in a more reliable and readable way:

from freezegun import freeze_time

def test():
    assert datetime.datetime.now() != datetime.datetime(2012, 1, 14)
    with freeze_time("2012-01-14"):
        assert datetime.datetime.now() == datetime.datetime(2012, 1, 14)
    assert datetime.datetime.now() != datetime.datetime(2012, 1, 14)