[mistral] Create for all client and non-client lib wallaby branch

This creates the stable/wallaby branch for all client and non-client libraries
now that we are past the lib freeze on March 11.

If a team wants to wait for a specific patch to make it to the library,
someone from the team can -1 the patch to have it held,or update that
patch with a different commit SHA.

Patches with no response will be merged by Friday, March 19.

Change-Id: Ibff60e6a94654e76befd9fa4fdaebe39389c0903

deliverables/wallaby/mistral-extra.yaml

@@ -11,3 +11,6 @@ releases:
     projects:
       - repo: openstack/mistral-extra
         hash: dfc6c56490eb358018f79822ae9847e2be89d8b3
+branches:
+  - name: stable/wallaby
+    location: 11.0.0

deliverables/wallaby/mistral-lib.yaml

@@ -11,3 +11,6 @@ releases:
     projects:
       - repo: openstack/mistral-lib
         hash: 95724c5ad0d249e8774d12c306c89dba000e2d33
+branches:
+  - name: stable/wallaby
+    location: 2.4.0

deliverables/wallaby/python-mistralclient.yaml

@@ -11,3 +11,6 @@ releases:
     projects:
       - repo: openstack/python-mistralclient
         hash: 20a10f0fb54e98368afc92639f6a15ed4a0aa218
+branches:
+  - name: stable/wallaby
+    location: 4.2.0