Release final mistral-lib for Xena

This proposed a release for mistral-lib to get any final merged changes
out prior to the lib freeze 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 Monday, August 23.

$ git log --oneline --no-merges 2.4.0..44c33f2
44c33f2 [community goal] Update contributor documentation
2068c9c setup.cfg: Replace dashes with underscores
b49b6e4 Use py3 as the default runtime for tox
83b2d7e Dropping lower constraints testing
adb30bd Update master for stable/wallaby

Signed-off-by: Hervé Beraud <hberaud@redhat.com>
Change-Id: Ie8592c03aaf4b82f9159333b222cd78c23a430c1

deliverables/xena/mistral-lib.yaml

@@ -6,3 +6,8 @@ team: mistral
 type: library
 repository-settings:
   openstack/mistral-lib: {}
+releases:
+  - version: 2.5.0
+    projects:
+      - repo: openstack/mistral-lib
+        hash: 44c33f2ccd8b059f68db59114c71ba95dfae574d