Proposing Xena RC1 for mistral

This proposed a RC1 release for mistral to get any merged changes
out prior to the RC1 deadline for Xena going into effect.

If the team is ready to proceed, please leave a +1 to acknowledge this
release and we will process right away. If the team is working on any
final merges, leave a -1 with some detail on the status and update the
patch with the new commit hash to use when ready.

Patches with no response will be merged by Thursday, September 16.

$ git log --oneline --no-merges 12.0.0..b2d6de56
b2d6de56 Fix unit test failures caused by type mismatch
22e822dd Remove references to sys.version_info
0bba6972 Replace oslo_utils.fnmatch with fnmatch
5055da91 Replace deprecated tenacity.Retrying.call
de880e80 Fix unit test failures
b64ba9a4 [Doc] Moving to OFTC
0ee7a365 setup.cfg: Replace dashes with underscores
b2df56e8 Dropping lower constraints testing
b1ee1347 Use py3 as the default runtime for tox
9e44f73a Add Python3 xena unit tests
3846b9e6 Update master for stable/wallaby
85b9b525 Change get-pip url

Signed-off-by: Hervé Beraud <hberaud@redhat.com>
Change-Id: I48e723a5e4b9f588e9237a269fb0380541e91455

deliverables/xena/mistral.yaml

@@ -6,3 +6,11 @@ team: mistral
 type: service
 repository-settings:
   openstack/mistral: {}
+releases:
+  - version: 13.0.0.0rc1
+    projects:
+      - repo: openstack/mistral
+        hash: b2d6de569c7bba96cd3179189ffbcee6b7a28c1f
+branches:
+  - name: stable/xena
+    location: 13.0.0.0rc1