Install Tempest in utility container

* Tempest playbook added to openstack dir
* glance_image module added for creating images and gathering image
  facts
* tempest_resources role added to create tempest prerequisites (cirros
  image, tenants)
* tempest role added for configuring tempest
* rpc_tempest_gate.sh added to /root in utility containers
Merge pull request #227 from hughsaunders/utility_tempest

Install Tempest in utility container
Move duplicated glance roles into a common file.