Read CLI options from kitchen.yml

Apologies if this feature is already covered.  If so, it isn't documented in the master README.

I would like the ability to specify the test kitchen CLI options from kitchen.yml.  See [lines 4-5](https://gist.github.com/atomic-penguin/5629656#file-kitchen-yml-L4) in this gist for an example.  In a nutshell, I would prefer not to have to specify `--destroy=never` or `--parallel` on the command line each time.