title: Angular $resource endpoint with two parameters
body: <p>I've got a setup using a service to handle $resource that is as follows:</p>
  
  <p><strong>Service</strong></p>
  
  <pre><code>factory('EventSlot', ['$resource', function ($resource){
      return $resource('/api/events/:id/slots/:slotId', {id: "@Id", slotId: "@slotId"},
      {
          signup: {
             method: 'PUT'
          }
       });
   }]);
  </code></pre>
  
  <p><strong>Calling Function</strong></p>
  
  <pre><code>EventSlot.signup({id: $scope.id, slotId: $scope.signUpSlot.id}, $scope.signUpSlot);
  </code></pre>
  
  <p>However, when the PUT call actually goes through it goes through to the endpoint:
  <code>/api/events/123/slots/</code> where 123 is the appropriate <code>@Id</code> however <code>@slotId</code> never gets attached.  So, what I want is <code>/api/events/123/slots/456</code> but that never happens.</p>