Cleaning up application categories.

Change-Id: Id3c937323123b6089cedf7b31cd01151f6aca8e1
diff --git a/apps/vtn/BUCK b/apps/vtn/BUCK
index 3cb6dd3..3afd56d 100644
--- a/apps/vtn/BUCK
+++ b/apps/vtn/BUCK
@@ -8,6 +8,7 @@
 onos_app (
   title = 'OPNFV',
   url = 'http://onosproject.org',
+  category = 'Integration',
   included_bundles = BUNDLES,
   description = 'ONOS framework applications',
 )