Add favicon

Author: pengbins

img/favicon.png

@@ -11,6 +11,8 @@
   <link href="fonts/materialIcons.css" rel="stylesheet">
   <link href="fonts/roboto.css" rel="stylesheet">
   <link rel="stylesheet" href="lib/react-select.css">
+  <link rel="icon" href="img/favicon.png" />
+
   <style>
     html, body {
       height: 100%;