Merge pull request #53 from cowboy129/master

Fix MatchError
Fixed: do not try to call isDefinedAt in Receive, which may run some
logic at once.
Changed close-timeout log from WARN to INFO.
Dependent on spray-websocket 0.1.2-RC1
Change socketio heartbeat initial delay

random value between 0 and min(heartbeatInterval, closeTimeout) * 0.618