ignore coverage files and DS_Store.
Total branch-test-coverage achieved.

After spending a signficant time muddling around with this, I finally
spent enough time configuring the setup.py file and my local
virtualenv to the point where I could run the tests.

To achieve the full branch coverage with the try/except branch for the
south import I followed the advice on two stackoverflow questions:

http://stackoverflow.com/questions/22637768/i-want-to-cause-an-importerror/22638083?noredirect=1#22638083

and

http://stackoverflow.com/questions/2481511/mocking-importerror-in-python
update path to be relative to localized_recurrence.