emit
Emits a socket event.
    server.emit(event, ...data, [ackFn])
  
  Emits a socket event.
server.emit("news", data1, data2, function(ackData){
  console.log("Client acknowledged", ackData);
});
  
  Parameters
- event 
{string}:The name of the socket event.
 - data 
{*}:Data to be sent with the event. Socket.io allows to send more than one data objects.
 - ackFn 
{function}:The acknowledgement function that will be executed if the receiver calls the acknowledgement callback.