Vagrant changes

Update the vagrantfile to create 4 VM's: Ubuntu 12.04, Ubuntu 14.04, Centos 6 and Centos 7 boxes, and connect chef-solo as the provisioner.
Can we make this only happen when you pass a certain param? I'd like to keep the machine it brings up 'clean' so we can test how it will work for manual deploys against a non-vagrant server.