notifications: fix update notification

the notification wasn't working because this was in apptask and the apptask died
before it could send out the email. we now move the notification to box process
and also remove the email notification.

src/auditsource.js

@@ -3,7 +3,6 @@
 exports = module.exports = {
     CRON:  { userId: null, username: 'cron' },
     HEALTH_MONITOR: { userId: null, username: 'healthmonitor' },
-    APP_TASK: { userId: null, username: 'apptask' },
     EXTERNAL_LDAP_TASK: { userId: null, username: 'externalldap' },
     EXTERNAL_LDAP_AUTO_CREATE: { userId: null, username: 'externalldap' },