Fix broken celluloid dependent version * celluloid 0.12.x depends on any versions of celluloid/timers   * but celluloid/timers newly released versions isn't compatible w/ celluloid 0.12.x   * so tests fails * With celluloid 0.16.0, tests runs successfully
Fix broken celluloid dependent version
* celluloid 0.12.x depends on any versions of celluloid/timers
  * but celluloid/timers newly released versions isn't compatible w/ celluloid 0.12.x
  * so tests fails
* With celluloid 0.16.0, tests runs successfully

authorNari/msgpack-rpc-over-http