Adding google anayltics tracking

app/index.html

@@ -38,5 +38,16 @@
 
   <script src="lib.js" type="text/javascript"></script>
   <script src="app.js" type="text/javascript"></script>
+  <% if (uaTracking) { %>
+    <script>
+      (function(i,s,o,g,r,a,m){i['GoogleAnalyticsObject']=r;i[r]=i[r]||function(){
+      (i[r].q=i[r].q||[]).push(arguments)},i[r].l=1*new Date();a=s.createElement(o),
+      m=s.getElementsByTagName(o)[0];a.async=1;a.src=g;m.parentNode.insertBefore(a,m)
+      })(window,document,'script','//www.google-analytics.com/analytics.js','ga');
+
+      ga('create', '<%= uaTracking %> ', 'auto');
+    </script>
+  <% } %>
+
 </body>
 </html>