enable unit test for vrouter
skips unit tests due to support status
updates gateway configuration on gw ip change
removes unused parameter from driver clear_gateway
adds helper functions to router API client
Change-Id: I5df3b24beb03e0d5af7dda4ad61b687482308508
The structure for the unit test tree in neutron has
been changed, so we need to update our unit tests
accordingly.
policy_file override is no longer required, as it has
been fixed in neutron upstream.
Change-Id: Id5d2d6f7d97c1c68c4dfe864d4916dcf757ddf5d