fix(timeouts): use code 504 when erroring due to nsurl timeout
fix(timeouts): use code 504 when erroring due to nsurl timeout

michaelkirk/SocketRocket,erikprice/SocketRocket,michaelkirk/SocketRocket,michaelkirk/SocketRocket,michaelkirk/SocketRocket,erikprice/SocketRocket,michaelkirk/SocketRocket,erikprice/SocketRocket,erikprice/SocketRocket,erikprice/SocketRocket,erikprice/SocketRocket,michaelkirk/SocketRocket,erikprice/SocketRocket,michaelkirk/SocketRocket