Delete unused Django app tests.py.
Delete unused Django app tests.py.

Our unit tests are in a `tests` subdirectory, so we don't need the file, and the presence of both interfered with test discovery.

HaroldMills/Vesper,HaroldMills/Vesper,HaroldMills/Vesper,HaroldMills/Vesper,HaroldMills/Vesper