issue #6: Reduce timeout while waiting for pong.
issue #6: Reduce timeout while waiting for pong.

As every write causes snap to reset the connection timeout we want to
ensure that our own pings are not preventing an eventual timeout if
clients do not send back pong messages. To achieve this we lower the
timeout while waiting for a pong.

GaloisInc/websockets-snap,GaloisInc/websockets-snap