Notifications dependency

[bdelwood]

OS: Ubuntu 16.10, headless
Python: 2.7.1 (Miniconda distro)
Autorippr: 1.7

Pushover notifications weren't working. I just got
2017-01-07 18:53:23 - Pushover - INFO - Pushover message sent successfully
from the logs.

I took a peek at the notifications.py and pushover.py files and discovered chump as a dependency. All works after finding it and installing with pip. Maybe chump should be added to the dependencies or have notifications included on the "test" script.

[JasonMillward]

Good point. I will add the dependancy test as well.