Update Media Player Library versoin

Author: shawngit

mpl.html

@@ -26,7 +26,7 @@
     <!--
         Cast Media Library
     -->
-    <script type="text/javascript" src="//www.gstatic.com/cast/sdk/libs/mediaplayer/0.4.0/media_player.js"></script>
+    <script type="text/javascript" src="//www.gstatic.com/cast/sdk/libs/mediaplayer/0.5.0/media_player.js"></script>
     <script type="text/javascript" src="mpl.js"></script>
 
     <style>