Socket doesn't keepalive

gistfile1.txt

var request = require('request');                                                                                                                              
function go() {                                                                                                                                                
  request('https://api.twitter.com/robots.txt', function (error, response, body) {                                                                             
    console.log(body);                                                                                                                                         
  })                                                                                                                                                           
}                                                                                                                                                              
setInterval(go, 1000);