Add Tobiko to gate jobs

Adding devstack-tobiko-octavia job for traffic tests
to gate check.

Related: https://issues.redhat.com/browse/OSPRH-11478
Change-Id: Iaa1cc88e95a24da18057432a8e3a05df2b8a3316

Author: chrisbug

zuul.d/project.yaml

@@ -27,3 +27,7 @@
         - ovn-octavia-provider-functional-release
         - ovn-octavia-provider-functional-master
         - ovn-octavia-provider-tempest-release
+        - devstack-tobiko-octavia:
+            voting: true
+            vars:
+              pytest_addopts_global: "--skipregex=OctaviaBasicTrafficScenarioTest"