berks wrap command

Greetings!

The idea here is to create a ```berks wrap``` subcommand that helps quickly generate a wrapper cookbook. I've been doing this a lot lately and found myself not needing a lot of the same options and doing quite a bit of boilerplate for a basic wrapper cookbook. Right now this command is not feature complete and I'm starting this PR to see if such a command is a good idea to add in to a future release of Berkshelf. I'm also not sure if this should end up being a separate command or some kind of option to the cookbook command?