title: Custom directive not loading template
body: <p>app.js file:</p>
  
  <pre><code>var app = angular.module('fruitStore', []);
  
  app.directive('productTitle', function(){
     return {
     restrict: 'E',
     templateUrl: 'product-title.html'
    };
  });
  </code></pre>
  
  <p>index.html</p>
  
  <pre><code>&lt;product-title&gt;&lt;/product-title&gt;
  </code></pre>
  
  <p>product-title.html</p>
  
  <pre><code>{{ product.name}}
  &lt;em class="pull-right"&gt;{{ product.price | currency}}&lt;/em&gt;
  </code></pre>
  
  <p>But the directive is not loading the template. What am I missing?</p>