liberty: release oslo.service 0.9.1

This release contains two major bugfixes to make signal handling more reliable.
For example, the bugs caused random failures on Grenade tests.

git log 0.9.0..liberty --oneline:

    8b6e2f6 Fix race condition on handling signals
    eb1a4aa Fix a race condition in signal handlers
    0caf56e Updated from global requirements
    56b3ff0 ThreadGroup's stop didn't recognise the current thread correctly
    9bee390 doing monkey_patch for unittest.
    5a20d1f Updated from global requirements
    d81e4f2 Update .gitreview for stable/liberty

Add also send-announcements-to and include-pypi-link fields to
oslo.service.yaml (send-announcements-to is mandatory).

Change-Id: I8e69d39cfa21ec2f656ea80ce2c4d4d13ca0d769
Related-Bug: 1524907
Related-Bug: 1538204

deliverables/liberty/oslo.service.yaml

@@ -1,5 +1,7 @@
 ---
 launchpad: oslo.service
+send-announcements-to: openstack-dev@lists.openstack.org
+include-pypi-link: yes
 releases:
   - version: 0.1.0
     projects:
@@ -37,3 +39,7 @@ releases:
     projects:
       - repo: openstack/oslo.service
         hash: fad5b04d5933ae3e08b8991d18dc51089cf9b8d1
+  - version: 0.9.1
+    projects:
+      - repo: openstack/oslo.service
+        hash: 8b6e2f64e8f82ec736a4c5b792d448ad7faf051f