Travis-CI Integration

Basic config for getting us up and running with Travis-CI (for continuous integration).

Here's the first successful build from my fork:

https://travis-ci.org/dowski/diesel/builds/4772544

Steps one and two at the following link should be all that's needed once this is merged.

http://about.travis-ci.org/docs/user/getting-started/#Step-one%3A-Sign-in