Updated tk-multi-about to v0.3.0

Release notes: https://github.com/shotgunsoftware/tk-multi-about/wiki/Release-Notes#v030

Author: Jean-François Boismenu

env/includes/common/apps.yml

@@ -19,7 +19,7 @@ includes:
 
 common.apps.tk-multi-about:
   location:
-    version: v0.2.9.rc
+    version: v0.3.0
     type: app_store
     name: tk-multi-about