Comment on vlan_create

Change-Id: I4d91ac1418976966ee58baa08851a2b96d309a61
diff --git a/db/db.py b/db/db.py
index c355f40..57d3107 100644
--- a/db/db.py
+++ b/db/db.py
@@ -69,6 +69,9 @@
             raise
         return port_id
 
+    # Create a new vlan in the database. We locally add a creation
+    # timestamp, for debug purposes. If vlans seems to be sticking
+    # around, we'll be able to see when they were created.
     def create_vlan(self, name, tag, is_base_vlan):
         try:
             dt = datetime.datetime.now()