Don't use kalabox variable in multiple scopes

Just a heads up, but I think this might come back to bite you later:
https://github.com/kalamuna/kalastack/blob/2.x/Vagrantfile#L110

Notice that you're using `kalabox` at both the vm-level config and also at the provisioner level. I don't think it's hurting you now, but the provisioner-level configs might override the higher level ones if they share key names

The official vagrant template would suggest that `kalabox` and `puppet_server` are a little more fitting:
https://github.com/mitchellh/vagrant/blob/master/templates/commands/init/Vagrantfile.erb#L78

I might recommend we stick with their approach, if only for clarity? Whaddaya think? :)