Upgrade Celery to version 4.1.
Upgrade Celery to version 4.1.

Mte90/remo,Mte90/remo,akatsoulas/remo,mozilla/remo,mozilla/remo,akatsoulas/remo,Mte90/remo,akatsoulas/remo,akatsoulas/remo,Mte90/remo,mozilla/remo,mozilla/remo