title: ng-grid columnDefs showing {{ col.displayName }} and {{ grid.getCellValue }}
body: <p>i have this controller:</p>
  
  <pre><code>$scope.allOrders = [];
  OrdersFactory.query().$promise.then(function(data) {
   $scope.allOrders = data;
  });
  $scope.gridOptions = {
      data: 'allOrders',
      columnDefs: [
          { name:'document_no', field: 'document_no' },
          { name:'waiter_name', field: 'waiter_name' }
      ]
  };
  </code></pre>
  
  <p>factory will get this data:</p>
  
  <pre><code>[
      {
          "id": 21, 
          "document_no": "RAC_21", 
          "waiter_name": "Name 2"
      }, 
      {
          "id": 20, 
          "document_no": "RAC_20", 
          "waiter_name": "Name"
      },
      ...
  ]
  </code></pre>
  
  <p>And this is result:
  <img src="https://i.stack.imgur.com/6sFh9.png" alt="enter image description here"></p>
  
  <p>Why doesn't it show my data and heading for table?</p>