Improve panel and block managers

package.json

@@ -1,7 +1,7 @@
 {
   "name": "grapesjs",
   "description": "Free and Open Source Web Builder Framework",
-  "version": "0.7.8",
+  "version": "0.8.1",
   "author": "Artur Arseniev",
   "license": "BSD-3-Clause",
   "homepage": "http://grapesjs.com",

src/block_manager/index.js

@@ -119,7 +119,8 @@ module.exports = () => {
       },
 
       /**
-       * Get all available categories
+       * Get all available categories.
+       * Is possible to add categories only with blocks via 'add()' method
        * @return {Array|Collection}
        */
       getCategories() {

test/specs/block_manager/index.js

@@ -1,7 +1,7 @@
 var BlockManager = require('block_manager');
 var BlocksView = require('./view/BlocksView');
 
-describe.only('BlockManager', () => {
+describe('BlockManager', () => {
 
   describe('Main', () => {