Upstream merge
Upstream merge

Moved instance type extra specs tests to extensions directory.

Added os- prefix to extra specs API alias.

Pegged pep8 venv version to 0.6.1

hyakuhei/cleantox,zancas/hacking,zancas/hacking,openstack-dev/hacking,openstack-dev/hacking,emonty/oslo-hacking,hyakuhei/cleantox,emonty/oslo-hacking