add whisper version message to demo app

Author: iurimatias

demo/app/index.html

@@ -77,6 +77,7 @@ <h3>Get file or image from ipfs</h3>
       </div>
       <div role="tabpanel" class="tab-pane" id="communication">
         <div class="error alert alert-danger" role="alert">The node you are using does not support Whisper</div>
+        <div class="errorVersion alert alert-danger" role="alert">The node uses an unsupported version of Whisper</div>
         <div id="communication-controls">
         <h3>Listen To channel</h3>
         <div class="form-group form-inline listen">

demo/package.json

@@ -10,7 +10,7 @@
   "license": "ISC",
   "homepage": "",
   "devDependencies": {
-    "embark": "^2.5.0",
+    "embark": "/Users/iurimatias/Projects/embark-framework",
     "mocha": "^2.2.5"
   }
 }