Fix /etc/hosts generation
Packstack AIO: launch instance and install/test in openstack env

* Had to duplicate part of the get_nodes role for now
* Had to duplicate part of the set_facts
tempest: install venv script
tempest: pip conf to cache downloads
tempest: openstack-setup task
tempest: task to setup tempest
tempest: stores test config in vars
tempest: parameterizes tempest_init.pp
tempest: script to setup tempest
tempest: task to setup tempest
tempest: script to run nosetest/testr
Refactors tempest role to sub-tasks
tempest: adds TODO/NOTES to config
tempest: minor updates to usage section of run_tempest.sh
tempest: run_tempest.sh ignore test run failure
Flavor: update packstack to flavor_id var