updated regex for controller/stylesheet replace

[Existing code](https://github.com/infinitered/rmq/blob/0fb018c2b447a7aa15dc2df184d258b7a5f2d73a/bin/rmq#L109) was replacing the word controller, but not fixing the extra underscore.  E.g.

`rmq create controller neat_cool_controller` would generate files with double underscores from the replace: ergo `neat_cool__controller`

Updated the regex to pick it up.