Fix the `vagrant up` situation

Cloning the repository and issuing a `vagrant up` resulted in scary red fail messages. These commits tidy that situation up a little bit.

Vagrantfile has also been cleaned up to look more like the one `meez` creates, and extended to silence the annoying ssl_verify_mode message.
Did you want to move the elk_nodes variable as well? I think I changed that so people could override it if they didn't have chef-zero vs. just breaking.