Definitely and utterly from "the department of it's easy when you know how".

I searched and searched for this and finally found out how to do it. I always figured it'd be a setting in the .travis.yml file, but it's not. So just doing my bit to broaden the search horizon.

This is necessary now for now that I want to test under Python 2 and 3 - if it tries to run both at the same time it'll fail somewhere along the way as both will be interacting with the same account.