Added setplaybackrate method in each adapter

package.json

@@ -1,7 +1,7 @@
 {
   "title": "Player.js",
   "name": "@gumlet/player.js",
-  "version": "1.0.3",
+  "version": "1.0.4",
   "homepage": "http://github.com/gumlet/player.js",
   "main": "dist/player.min.js",
   "repository": {

src/adapters/html.js

@@ -92,6 +92,10 @@ playerjs.HTML5Adapter.prototype.init = function(video){
   receiver.on('setLoop', function(value){
     video.loop = value;
   });
+
+  receiver.on('setPlaybackRate', function(value){
+    video.playbackRate = value;
+  });
 };
 
 /* Call when the video has loaded */

src/adapters/mock.js

@@ -95,6 +95,10 @@ playerjs.MockAdapter.prototype.init = function(){
   receiver.on('setLoop', function(value){
     video.loop = value;
   });
+
+  receiver.on('setPlaybackRate', function(value){
+    video.speed = value;
+  });
 };
 
 /* Call when the video has loaded */

src/adapters/video.js

@@ -99,6 +99,10 @@ playerjs.VideoJSAdapter.prototype.init = function(player){
   receiver.on('setLoop', function(value){
     player.loop(value);
   });
+
+  receiver.on('setPlaybackRate', function(value){
+    player.playbackRate(value);
+  });
 };
 
 /* Call when the video.js is ready */