Synchronize .travis.yml and Rakefile

.travis.yml is now more centrally managed via modulesync. Rakefile now has a validation block so that .travis.yml can call rake validate.
![1377879520886](https://cloud.githubusercontent.com/assets/9492/3417125/ea601c8a-fe34-11e3-8cc6-e6007f6a5b7c.jpg)