Adding custom elements needs to wait until after polymer-ready

polymer_setup.js

// 1. Load Polymer before any code that touches the DOM.
var script = document.createElement("script");
script.src = "/base/bower_components/webcomponentsjs/webcomponents.js";
document.getElementsByTagName("head")[0].appendChild(script);

// Delay Jasmine specs until WebComponentsReady
var POLYMER_READY = false;
beforeEach(function(done) {
  window.addEventListener('polymer-ready', function () {
    
    // import custom elements
    var link = document.createElement("link");
    link.rel = "import";
    link.href = "/base/elements/twt-user-badge.html";
    document.getElementsByTagName("head")[0].appendChild(link);

    POLYMER_READY = true;
    done();
  });
  if (POLYMER_READY) done();
});