Add openstack-salt-formula project

This is a SaltStack formula used for create an OpenStack deployment by
using other related salt-formulas. i.e. keystone-salt-formula,
nova-salt-formula, glance-salt-formula, etc.

Change-Id: I51751edf94d0857e7a4b237a22697718b6c58baf
Merge "Add openstack-salt-formula project"