apns feedback service

[diwu1989]

please add in support for the apns feedback service so that periodically, deregistered devices are cleaned out of the database, thankyou!

[tarekskr]

+1

[Droppix]

+1

[flovilmart]

There's no need for the feedback service anymore, if you're using the latest parse-server you can set PARSE_SERVER_CLEANUP_INVALID_INSTALLATIONS=1 and it will remove the invalid device tokens ('Unregistered' || 'BadDeviceToken')

https://github.com/parse-community/parse-server/blob/master/src/StatusHandler.js#L198