New neutron-lib release

It was discussed on today's Neutron team meeting [1] that as soon
as patch [2] will be merged we would like to release new version of
neutron-lib.
As [2] is merged now, we can release new version.

[1] http://eavesdrop.openstack.org/meetings/networking/2019/
    networking.2019-08-13-14.00.log.html#l-154
[2] https://review.opendev.org/#/c/670849/

Change-Id: If803cac6f2e5f94cf71d93e63ad4a6272a8aacfd

deliverables/train/neutron-lib.yaml

@@ -19,3 +19,7 @@ releases:
     projects:
       - repo: openstack/neutron-lib
         hash: 7a58374fde64fdc14e327940dde6bea4a8a39345
+  - version: 1.29.0
+    projects:
+      - repo: openstack/neutron-lib
+        hash: 104627a9336c2cff6808dc0024c43c6b0a7a723c