Adding Tobiko Test To CI

Adding zuul job to run traffic tests with Tobiko.
These tests will run traffic through a devstack instance
to validate load balancer.

Set voting flag to true on check job.
Added skip flag to remove round robin tests.

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

Change-Id: Idb7c8d02a494c5d4cc376f7d98ce8f63b7a0551c

zuul.d/project.yaml

@@ -17,6 +17,10 @@
             voting: false
         - kuryr-kubernetes-tempest-ovn-provider-ovn:
             voting: false
+        - devstack-tobiko-octavia:
+            voting: true
+            vars:
+              pytest_addopts_global: "--skipregex=OctaviaBasicTrafficScenarioTest"
     gate:
       fail-fast: true
       jobs: