Fix .coffee.js Style Guide Issue

https://trello.com/c/QdQKEB6e
"A lot, if not most CoffeeScript files have .coffee.js extensions. It's much like .haml.html or .erb.html."

I don't think I've seen any of these extensions on a project yet in my career. Is there an app you can refer me to that uses these?

> On Nov 18, 2014, at 7:38 PM, Greg Lazarev <notifications@github.com> wrote:
> 
> A lot, if not most CoffeeScript files have .coffee.js extensions. It's much like .haml.html or .erb.html.