title: Updating Min and Max values on Md-Slider shows wrong information
body: <p>I have a very minimilistic example on codepen. I have an md-slider, with bound min and max values. The next thing i attempt to do is to use a button handler to change these bound values and also change the sliders current position.</p>
  
  <pre><code>//Initial setup
  $scope.myslider={};
  $scope.myslider.min = 100;
  $scope.myslider.max =1000;
  $scope.myslider.val = 500;
  </code></pre>
  
  <p>Here is my handler for the button updating the min max and selected value</p>
  
  <pre><code>$scope.buttonhandler = function()
  {
  $scope.myslider.min =0;
  $scope.myslider.max =100;
  $scope.myslider.val = 5;
  };
  </code></pre>
  
  <p>When the button handler is triggered, the slider position is off to the extreme right. somewhere close to 100% instead of the 5%  where i expect it to be at.</p>
  
  <p>Is there something wrong in my approach <a href="http://codepen.io/anon/pen/YNLNEQ" rel="nofollow noreferrer">codepen</a>. </p>