Publish Charm to Charmhub Channel 'latest/edge'

Upload and publish every successful merge to the 'latest/edge' channel
on Charmhub.

Change-Id: I26d583affba50914530eb0f6c19f1ee145ac6a75
diff --git a/zuul.d/charm-cinder-storpool-iscsi.yaml b/zuul.d/charm-cinder-storpool-iscsi.yaml
index 783003d..b1fa8e2 100644
--- a/zuul.d/charm-cinder-storpool-iscsi.yaml
+++ b/zuul.d/charm-cinder-storpool-iscsi.yaml
@@ -145,6 +145,11 @@
             branches: master
         - zaza-functional-focal-ussuri:
             branches: master
+    post:
+      jobs:
+        - publish-to-charmhub:
+            vars:
+              channel: latest/edge
     experimental:
       jobs:
         - zaza-functional-focal-ussuri-edge: