added basic celery support for leases
added basic celery support for leases

Solinea/goldstone-server,Solinea/goldstone-server,slashk/goldstone-server,slashk/goldstone-server,slashk/goldstone-server,slashk/goldstone-server,slashk/goldstone-server,Solinea/goldstone-server,Solinea/goldstone-server,Solinea/goldstone-server