Add Tempest gate job for stable/rocky

Now we have stable/rocky branch ready for devstack
and so does for all service projects.

This commit adds the Tempest testing for stable/rocky
by adding new jobs running on stable/rocky version of
openstack.
Depends-On: https://review.openstack.org/#/c/596276/

Change-Id: I88d4b121bf461495b357916f4b7827b46a2fbc46

.zuul.yaml

@@ -163,6 +163,16 @@
         CINDER_ENABLED_BACKENDS: lvm:lvmdriver-1,lvm:lvmdriver-2
       tempest_concurrency: 2
 
+- job:
+    name: tempest-full-rocky
+    parent: tempest-full
+    override-checkout: stable/rocky
+
+- job:
+    name: tempest-full-rocky-py3
+    parent: tempest-full-py3
+    override-checkout: stable/rocky
+
 - job:
     name: tempest-full-queens
     parent: tempest-full
@@ -314,6 +324,26 @@
               - ^setup.cfg$
               - ^tempest/hacking/.*$
               - ^tempest/tests/.*$
+        - tempest-full-rocky:
+            irrelevant-files:
+              - ^(test-|)requirements.txt$
+              - ^.*\.rst$
+              - ^doc/.*$
+              - ^etc/.*$
+              - ^releasenotes/.*$
+              - ^setup.cfg$
+              - ^tempest/hacking/.*$
+              - ^tempest/tests/.*$
+        - tempest-full-rocky-py3:
+            irrelevant-files:
+              - ^(test-|)requirements.txt$
+              - ^.*\.rst$
+              - ^doc/.*$
+              - ^etc/.*$
+              - ^releasenotes/.*$
+              - ^setup.cfg$
+              - ^tempest/hacking/.*$
+              - ^tempest/tests/.*$
         - tempest-full-queens:
             irrelevant-files:
               - ^(test-|)requirements.txt$
@@ -422,6 +452,8 @@
               - ^tempest/tests/.*$
     periodic-stable:
       jobs:
+        - tempest-full-rocky
+        - tempest-full-rocky-py3
         - tempest-full-queens
         - tempest-full-queens-py3
         - tempest-full-pike