Update Stats element to use new directory layout

appengine/swarming/elements/res/imp/index/swarming-index-demo.html

Index: appengine/swarming/elements/res/imp/index/swarming-index-demo.html
diff --git a/appengine/swarming/elements/res/imp/index/swarming-index-demo.html b/appengine/swarming/elements/res/imp/index/swarming-index-demo.html
index 98c638d7170e91940541e81815179356885a7c34..d053325cced3c49aca38247e2013e532bf8dcdc2 100644
--- a/appengine/swarming/elements/res/imp/index/swarming-index-demo.html
+++ b/appengine/swarming/elements/res/imp/index/swarming-index-demo.html
@@ -16,6 +16,9 @@
   <script src="/res/js/alias.js"></script>
   <script src="../../../node_modules/sinon/pkg/sinon-1.17.5.js"></script>
 
+  <!-- Makes a var called stats-->
+  <script type="text/javascript" src="index-overview-stats-demo.json"></script>
+
   <script type="text/javascript" charset="utf-8">
     sinon.format = function(object) {return JSON.stringify(object);}
     sinon.log = function(message) {console.log(message);};
@@ -52,6 +55,8 @@
     };
     server.respondWith("POST",  /^\/_ah\/api\/swarming\/v1\/server\/token/, JSON.stringify(token));
     server.respondWith("POST", /^\/api\/swarming\/v1\/server\/token/, JSON.stringify(token));
+
+    server.respondWith("GET", "/swarming/api/v1/stats/summary/minutes?duration=20",JSON.stringify(stats));
     </script>
 
     <link rel="import" href="swarming-index.html">