Add releasenote to tag the Tempest for Wallaby release

This commit adds the releasenote to tag Tempest for Wallaby
release.

Change-Id: I0993498a64bc42d7978285dca18e5ade5fa2b079
diff --git a/releasenotes/notes/tempest-wallaby-release-0f2cea5ccf63485e.yaml b/releasenotes/notes/tempest-wallaby-release-0f2cea5ccf63485e.yaml
new file mode 100644
index 0000000..25fb1f2
--- /dev/null
+++ b/releasenotes/notes/tempest-wallaby-release-0f2cea5ccf63485e.yaml
@@ -0,0 +1,17 @@
+---
+prelude: |
+    This release is to tag Tempest for OpenStack Wallaby release.
+    This release marks the start of Wallaby release support in Tempest.
+    After this release, Tempest will support below OpenStack Releases:
+
+    * Wallaby
+    * Victoria
+    * Ussuri
+    * Train
+
+    Current development of Tempest is for OpenStack Xena development
+    cycle. Every Tempest commit is also tested against master during
+    the Xena cycle. However, this does not necessarily mean that using
+    Tempest as of this tag will work against a Xena (or future release)
+    cloud.
+    To be on safe side, use this tag to test the OpenStack Wallaby release.