Run jsperf tests using phantomJS

jsperf_phantom.js

/* global document, require, setTimeout, phantom, console */
var jsPerfTest = "for-loops-with-caching";
var page = require("webpage").create();

page.open("http://jsperf.com/" + jsPerfTest, function() {
  "use strict";

  setTimeout(function() {
    page.evaluate(function() {
      var ev = document.createEvent("MouseEvents");
      ev.initEvent("click", true, true);
      document.querySelector("#run").dispatchEvent(ev);
    });
    setTimeout(function() {
      console.log("Test is complete");
      phantom.exit();
    }, 20000);
  }, 2000);
});