Remove path.py dependency (bug 1026472)

https://bugzilla.mozilla.org/show_bug.cgi?id=1026472

Stolen from mozilla/olympia#206
This cron job was commented out. I think it was finding all the old AMO addons and spewing MB sized emails so we turned it off. I'm not saying we shouldn't do this, though. Maybe after the addon purge from the db we won't need this at all?