Merge pull request #5 from mvimercati/master

Propagate client disconnections to the user.

Author: asanchezdelc

lib/mqtt.js

@@ -48,6 +48,10 @@ Cayenne.prototype.connect = function(callback) {
       return callback(null, self.client);
   });
 
+  this.client.on('close', function () {
+      self.emit("disconnect");
+  });
+    
   this.client.on('message', self.onMessage.bind(self));
 
   const cmdTopic = apiVersion + '/:username/'+THINGS+'/:thingId/cmd/:channel';