Skip incompatible with contrail neutron tests

Skip incompatible with contrail env neutron tests due to contrail
restrictions:
* Update of gateway is not supported.
https://bugs.launchpad.net/juniperopenstack/+bug/1466737
* Contrail backend don't allow removing of fixed ip from a port.
https://bugs.launchpad.net/juniperopenstack/+bug/1364677

Change-Id: I3ce0827f4cd154556a028fbaa932a0d031343257
Related-PROD: PROD-22168
2 files changed