Fixes to Vagrant testing support.

* Hacked around the fact that chef-zero provisioner doesn't understand .rb files by
running multiple provisioners.

* Fixed call to nova:identity_registration in os-compute-setup.rb role

note: chef run errors with 'No such file or directory - /etc/init.d/quantum-server restart', but can still start a compute instance and access via network, not a showstopper.

Change-Id: I4f9a0d10afb341b43809412e6e79d04b82b15555