Merge pull request #29 from sealevelresearch/fix-tests-on-python-2

Fix tests on Python 2
Fix test runner for Python 2 and 3

Hopefully for the last time!
Merge pull request #32 from sealevelresearch/fix-test-runner-again

Fix test runner for Python 2 and 3
Rename DateTimeTitle to DateTitle

Because it doesn't show any part of the time, so it's misleading.

Note that it still receives a prop called `datetime` because moment.js
works in datetimes.