Make cinderclient-py33 gating

As of 7fa5bc3005a31efb4373e168577a31b78323a1b4 cinderclient
passes python33 tests so make it gating

Change-Id: I91248ce6fe7c13a4a54adfe8c32a669abcfdb207
Signed-off-by: Chuck Short <chuck.short@canonical.com>
Merge "Make cinderclient-py33 gating"