title: ng-options and unique filter not displaying angular.js
body: <p>In my javascript I have an array</p>
  
  <pre><code>$scope.quoteList =        
      [
          {
              select: false,
              laymansDescription: "Nathan",
              quoteNumber: "ING-70440-21",
              version: "02",
              quoteDate: "Feb 5,2013",
              expirationDate: "Aug 5,2013",
              internalNotes: "This quote is using test data",
          },
          {
              select: false,
              laymansDescription: "Mitch",
              quoteNumber: "ING-70440-01",
              version: "02",
              quoteDate: "Feb 5,2013",
              expirationDate: "Aug 5,2013",
              internalNotes: "This quote is using test data",
          },
          {
              select: false,
              laymansDescription: "Stephen",
              quoteNumber: "ING-70440-01",
              version: "02",
              quoteDate: "Feb 5,2013",
              expirationDate: "Aug 5,2013",
              internalNotes: "This quote is using test data",
          }
      ];
  </code></pre>
  
  <p>And I am trying to make a selector that will only show unique quoteNumbers ie. ING-70440-21 and ING-70440-01. However when I try to use the 'unique' option in angular, nothing is showing up. </p>
  
  <pre><code>&lt;select class="form-control" ng-options="quote.quoteNumber for quote in quoteList | unique:'quoteNumber'" ng-model="quoteModel1" /&gt;
  </code></pre>
  
  <p>It works fine without the unique tag. What am I doing wrong? I pretty new to angular so it might be something really simple.</p>