Setup Travis CI

[Oli Peate]

As referenced in #33, it would be useful to setup CI with Travis. I can't add this because it requires admin privileges to the organisation (cc @igrigorik).

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Happy to contribute to the config once Travis CI has been enabled for this repo:
https://travis-ci.org/profile/postrank-labs

[Ilya Grigorik]

Done. Need to add .travis.yml..

[Oli Peate]

All done via #36

[Ilya Grigorik]

👍