Add Vagrantfile

Not sure if you're interested in merging this, but I've fixed a couple things I've run into:

 - Added Berkshelf 3 support to package script (`berks install --path` is deprecated in favor of `berks vendor`
 - Changed Berksfile source to newer `https://supermarket.getchef.com`
 - Added `Vagrantfile` to support multi-node cluster install, generate `node['mapr']['groups']` in Ruby `manifests.rb`

This should get things semi-working (except for that apt GPG error).