Re-enable UT for neutron-fwaas for services split

- Renable UT along with some minor fixes for import issues.

Change-Id: I5abacda42074ed23a005939256fbb606cecb9cc6
Partially-Implements: blueprint services-split
Do not list neutron in requirements.txt

It does not play nicely with openstack/requirements

Partially-Implements: blueprint services-split

Change-Id: I2fbe139ef78a8fb528b8ac67f00852ce7a29e4ae
Merge "Re-enable UT for neutron-fwaas for services split"
Merge "Do not list neutron in requirements.txt"