Add glance tests to gate script

Glance-swift (pubcloud) configuration was merged in
https://github.com/rcbops/jenkins-rpc/pull/69 so we can now test glance.

Related: https://github.com/rcbops/ansible-lxc-rpc/issues/472
Add cinder tests to gate script

Also adds basic neutron library and task to create a network in
tempest_resources.

Related: https://github.com/rcbops/ansible-lxc-rpc/issues/472
Merge pull request #567 from hughsaunders/add_cinder_gate_tests

Add cinder gate tests