[neutron] Create for all client and non-client lib xena branch

This creates the stable/xena branch for all client
and non-client libraries now that we are past the
lib freeze on September 02.

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, September 10.

Change-Id: I3d77d00f0ea8635c8b6983655a7a269a247553bd

deliverables/xena/neutron-lib.yaml

@@ -27,3 +27,6 @@ releases:
     projects:
       - repo: openstack/neutron-lib
         hash: 5ff14c63c86cd24720d41822d871a0a096aa821e
+branches:
+  - name: stable/xena
+    location: 2.15.0

deliverables/xena/os-ken.yaml

@@ -15,3 +15,6 @@ releases:
     projects:
       - repo: openstack/os-ken
         hash: f78a0ecdd4e6c219fe247002de2efa498d4fae1e
+branches:
+  - name: stable/xena
+    location: 2.1.0

deliverables/xena/ovsdbapp.yaml

@@ -18,3 +18,6 @@ releases:
     projects:
       - repo: openstack/ovsdbapp
         hash: 35c8eae020ef5300e08b7869e5da11dd0e2c500e
+branches:
+  - name: stable/xena
+    location: 1.12.0

deliverables/xena/python-neutronclient.yaml

@@ -19,3 +19,6 @@ releases:
     projects:
       - repo: openstack/python-neutronclient
         hash: 983f0abc58428c24d428362eebc26367ca1ae42e
+branches:
+  - name: stable/xena
+    location: 7.6.0