Add Tempest gate job for stable/yoga

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

This commit adds the Tempest testing for stable/yoga by adding
new jobs running on stable/yoga version of openstack.

Change-Id: Id731c26a0f134428094e8d830fb615695dffe10b
diff --git a/zuul.d/stable-jobs.yaml b/zuul.d/stable-jobs.yaml
index 5cc0dd0..f3b5716 100644
--- a/zuul.d/stable-jobs.yaml
+++ b/zuul.d/stable-jobs.yaml
@@ -1,5 +1,10 @@
 # NOTE(gmann): This file includes all stable release jobs definition.
 - job:
+    name: tempest-full-yoga
+    parent: tempest-full-py3
+    override-checkout: stable/yoga
+
+- job:
     name: tempest-full-xena
     parent: tempest-full-py3
     override-checkout: stable/xena