Reducing duplication for all commands
Reducing duplication for all commands

Most of the scripts were just going straight to `exec`. This just
brings most of that down to a single helper method to simplify everything a bit.

Also, removing `spawn` since it was never used.

joventuraz/hubot-chef,jjasghar/hubot-chef,skeenan947/hubot-chef,hubot-scripts/hubot-chef