title: Error when trying to run Polymer Starter Kit
body: <p>I'm trying to run the <a href="https://github.com/PolymerElements/polymer-starter-kit#getting-started" rel="nofollow">Polymer starter kit</a> but when I try to run 'gulp serve' (without the quotation) it opens the page on the browser, but it's not showing anything. </p>
  
  <p>When I inspect the JS console, I'm getting the following errors:</p>
  
  <p><a href="http://localhost:3000/bower_components/webcomponentsjs/webcomponents-lite.js" rel="nofollow">http://localhost:3000/bower_components/webcomponentsjs/webcomponents-lite.js</a> Failed to load resource: the server responded with a status of 404 (Not Found)
  <a href="http://localhost:3000/bower_components/iron-flex-layout/classes/iron-flex-layout.html" rel="nofollow">http://localhost:3000/bower_components/iron-flex-layout/classes/iron-flex-layout.html</a> Failed to load resource: the server responded with a status of 404 (Not Found)
  <a href="http://localhost:3000/bower_components/iron-icons/iron-icons.html" rel="nofollow">http://localhost:3000/bower_components/iron-icons/iron-icons.html</a> Failed to load resource: the server responded with a status of 404 (Not Found)
  <a href="http://localhost:3000/bower_components/iron-pages/iron-pages.html" rel="nofollow">http://localhost:3000/bower_components/iron-pages/iron-pages.html</a> Failed to load resource: the server responded with a status of 404 (Not Found)
  <a href="http://localhost:3000/bower_components/iron-selector/iron-selector.html" rel="nofollow">http://localhost:3000/bower_components/iron-selector/iron-selector.html</a> Failed to load resource: the server responded with a status of 404 (Not Found)
  <a href="http://localhost:3000/bower_components/paper-drawer-panel/paper-drawer-panel.html" rel="nofollow">http://localhost:3000/bower_components/paper-drawer-panel/paper-drawer-panel.html</a> Failed to load resource: the server responded with a status of 404 (Not Found)
  <a href="http://localhost:3000/bower_components/paper-header-panel/paper-header-panel.html" rel="nofollow">http://localhost:3000/bower_components/paper-header-panel/paper-header-panel.html</a> Failed to load resource: the server responded with a status of 404 (Not Found)
  <a href="http://localhost:3000/bower_components/paper-icon-button/paper-icon-button.html" rel="nofollow">http://localhost:3000/bower_components/paper-icon-button/paper-icon-button.html</a> Failed to load resource: the server responded with a status of 404 (Not Found)
  <a href="http://localhost:3000/bower_components/paper-item/paper-item.html" rel="nofollow">http://localhost:3000/bower_components/paper-item/paper-item.html</a> Failed to load resource: the server responded with a status of 404 (Not Found)
  <a href="http://localhost:3000/bower_components/paper-material/paper-material.html" rel="nofollow">http://localhost:3000/bower_components/paper-material/paper-material.html</a> Failed to load resource: the server responded with a status of 404 (Not Found)
  <a href="http://localhost:3000/bower_components/paper-menu/paper-menu.html" rel="nofollow">http://localhost:3000/bower_components/paper-menu/paper-menu.html</a> Failed to load resource: the server responded with a status of 404 (Not Found)
  <a href="http://localhost:3000/bower_components/paper-styles/paper-styles-classes.html" rel="nofollow">http://localhost:3000/bower_components/paper-styles/paper-styles-classes.html</a> Failed to load resource: the server responded with a status of 404 (Not Found)
  <a href="http://localhost:3000/bower_components/paper-toast/paper-toast.html" rel="nofollow">http://localhost:3000/bower_components/paper-toast/paper-toast.html</a> Failed to load resource: the server responded with a status of 404 (Not Found)
  <a href="http://localhost:3000/bower_components/paper-toolbar/paper-toolbar.html" rel="nofollow">http://localhost:3000/bower_components/paper-toolbar/paper-toolbar.html</a> Failed to load resource: the server responded with a status of 404 (Not Found)
  <a href="http://localhost:3000/bower_components/platinum-sw/platinum-sw-cache.html" rel="nofollow">http://localhost:3000/bower_components/platinum-sw/platinum-sw-cache.html</a> Failed to load resource: the server responded with a status of 404 (Not Found)
  <a href="http://localhost:3000/bower_components/platinum-sw/platinum-sw-register.html" rel="nofollow">http://localhost:3000/bower_components/platinum-sw/platinum-sw-register.html</a> Failed to load resource: the server responded with a status of 404 (Not Found)
  my-greeting.html:32 Uncaught ReferenceError: Polymer is not defined
  my-list.html:27 Uncaught ReferenceError: Polymer is not defined
  <a href="http://localhost:3000/bower_components/page/page.js" rel="nofollow">http://localhost:3000/bower_components/page/page.js</a> Failed to load resource: the server responded with a status of 404 (Not Found)</p>
  
  <p>Any help would be appreciated. Thank you</p>