Added Python tests to Travis

This will run the command `PYTHONPATH=.. nosetests -a '!slow'` and make sure it exits with status code 0, in addition to the JS tests already there. Note that the 15 second sleep is a Travis CI is to fix a known issue with Mongo. You can check https://travis-ci.org/JGulbronson/rmc/builds to see that they're passing.