Build with Travis CI

I'd like to help merge some pull requests, and travis can handily build pull requests to make sure they pass the tests. @technicalpickles, could you please go to [your Travis CI profile](https://travis-ci.org/profile) and toggle the switch for the homesick repository? I've tested it on my fork [here](https://travis-ci.org/wjbuys/homesick), and it seem happy. Once you've done that, merging this pull request should magically build new commits.