bump umd-example react version

Author: sergio-toro

example-umd/index.html

@@ -77,8 +77,8 @@
         <div class="inner"></div>
       </div>
     </div>
-    <script src="https://unpkg.com/react@0.14.8/dist/react.min.js"></script>
-    <script src="https://unpkg.com/react-dom@0.14.8/dist/react-dom.min.js"></script>
+    <script src="https://unpkg.com/react@16.8.6/umd/react.production.min.js"></script>
+    <script src="https://unpkg.com/react-dom@16.8.6/umd/react-dom.production.min.js"></script>
     <script src="https://unpkg.com/react-visibility-sensor@3.2.1/dist/visibility-sensor.min.js"></script>
     <script src="./main.js"></script>
   </body>