Renamed app/ to lib/ and api.coffee to app.coffee.

Improving consistency with other projects.
Upgraded to coffee-script 1.7.1.

Upgrading coffee-script just for the fun of it. The same way we upgraded Express.js and Node.js here before. Turning the API Blueprint API into one tiny little progressive app where we can see how the latest technologies perform.
Cleanup of @almad's testsuite proposal. Also, this fixes failing tests on CI.
Reverting coffee-script change. Will propose that one in separate branch.
Added HipChat / TravisCI integration.
Merge pull request #19 from apiaryio/hj/code-cleanup

Code cleanup
Charset handling and rejection of non-UTF-8 charsets.
Using req.get '...' instead of req.headers['...'] to prevent problems with case.