Merge pull request #214 from esheffield/snapshot_impersonate

Snapshot processor can now use pluggable auth systems
Fixes qonos for any pep8 failures
Merge pull request #215 from rackspace-titan/unused-imports-pep8-fix

Fixes qonos for any pep8 failures
Used python-novaclient==2.13

in pip-requires avoiding conflict with nova
Merge pull request #216 from rackspace-titan/upgrade-novaclient

Used python-novaclient==2.13
Ensure nova client is fetched from factory each time