claim expiration activates next claim
update status from waiting to active sets ttl
update status from waiting to active should sets active duration
updating ttl when status not active returns 409
update ttl while status acitve sets ttl
updating claim with negative ttl returns 400
updating expired claim returns 409
claim expiration does not activate other claims
whitespace
Merge pull request #22 from mark-burnett/add-expiration

Add expiration