Drop Python 3.3 tests in tox
Drop Python 3.3 tests in tox

We don't care about it anymore, we have Python 3.4

Change-Id: I20c58b9d4d9b926e548985c8224b5e514f5a1cf2

citrix-openstack-build/tooz,openstack/tooz,openstack/tooz,citrix-openstack-build/tooz