net_uv: Stub out setKeepAlive

lib/net_uv.js

@@ -76,6 +76,11 @@ Socket.prototype.setNoDelay = function() {
 };
 
 
+Socket.prototype.setKeepAlive = function(setting, msecs) {
+  /* TODO implement me */
+};
+
+
 Object.defineProperty(Socket.prototype, 'readyState', {
   get: function() {
     if (this._connecting) {