Merge pull request #81 from weseek/support/ie11

ensure to load babel-polyfill from CDN

lib/views/layout/layout.html

@@ -22,6 +22,17 @@
   <link rel="icon" type="image/png" href="/favicon-96x96.png" sizes="96x96">
   <link rel="icon" type="image/png" href="/android-chrome-192x192.png" sizes="192x192">
 
+  <!-- polyfills for IE11 -->
+  <script>
+    var userAgent = window.navigator.userAgent.toLowerCase();
+    if (userAgent.indexOf('msie') != -1 || userAgent.indexOf('trident') != -1) {
+      var scriptElement = document.createElement('script');
+      scriptElement.src = 'https://cdnjs.cloudflare.com/ajax/libs/babel-polyfill/6.23.0/polyfill.min.js';
+      var headElement = document.getElementsByTagName('head')[0];
+      headElement.appendChild(scriptElement);
+    }
+  </script>
+
   <!-- jQuery -->
   <script src="https://cdn.jsdelivr.net/jquery/3.2.1/jquery.min.js"></script>