Initial framework – dependancies and templating system

Create initial framework for thrashers. This also adds the only existing thrasher of `comment-us`.

What this allows you to do is create new thrashers from an existing template (that exists in `/template`). Then using the shell command outlined in the readme, watch for changes and build the appropriate json file for the snap. There's definitely more to come (Publish scripts, sass partials that do some generic templating, etc...) but I figured I'd keep this one brief-ish.

There will probably be better ways to do certain things, so do your worst... @phamann @rich-nguyen @ironsidevsquincy 

![200](https://cloud.githubusercontent.com/assets/1607666/4957769/b69b3ed0-66a7-11e4-98ac-c014dc641575.gif)

It makes me sad too. Unfortunately I don't believe LibSass is ready to production yet. At the moment it bawks at my hipster sass: https://github.com/guardian/thrashers/pull/2/files#diff-148a38facae54869dccc14917a04519fR303

When the new version comes out I will, test again and hopefully upgrade.