remove async from HammerJS script (angular#128)

Author: mmalerba

src/index.html

@@ -26,6 +26,6 @@
     ga('send', 'pageview');
   </script>
   <script async src='https://www.google-analytics.com/analytics.js'></script>
-  <script async src="https://ajax.googleapis.com/ajax/libs/hammerjs/2.0.8/hammer.min.js"></script>
+  <script src="https://ajax.googleapis.com/ajax/libs/hammerjs/2.0.8/hammer.min.js"></script>
 </body>
 </html>