Shaved multiple yaks to get this working.  Apparently our Ubuntu 14.04
bento box is broken; it hasn't got proper VMware tools support for
vmware_fusion 7.x.  So we have to bring the workstation VM up in two
steps so that the synced_folders will work, which allow chef_zero to
work. Also some shenanigans around the chef_cookbook_path.  In the end I
decided to point it at both the user's berkshelf cookbook directory as
well as the parent directory of this cookbook.  This allows you to get
the benefits of Berkshelf, even though it's not supported with chef_zero
in Vagrant.  Basically all you have to do is "berks install" before
running the deploy.sh script now.