use net.Socket instead of net.Stream

`net.Stream` is a undocumented legacy naming from node 0.x https://github.com/nodejs/node/blob/4ae320f2b3c745402955019d6a57a22ee2b8d3bd/lib/net.js#L1762

Author: chentsulin

lib/connection.js

@@ -19,7 +19,7 @@ var BINARY_MODE = 1
 var Connection = function (config) {
  EventEmitter.call(this)
  config = config || {}
- this.stream = config.stream || new net.Stream()
+ this.stream = config.stream || new net.Socket()
  this._keepAlive = config.keepAlive
  this.lastBuffer = false
  this.lastOffset = 0