py36: Fix unit tests
py36: Fix unit tests

Unit tests were only working on py35 and not py36, this is because
the unit test in test_api_validations were only checking for
py35. Use the six library to detect the python version used.

Change-Id: Iab10228e911a9efc0e18b04667596342ee949642
Signed-off-by: Chuck Short <61c7e57c8f71fbf1f6c3fcd85c16ccd0f494e116@redhat.com>

openstack/smaug,openstack/smaug