Add destroy method to TraitManager module

src/editor/model/Editor.js

@@ -769,7 +769,8 @@ export default Backbone.Model.extend({
       Parser,
       SelectorManager,
       StorageManager,
-      StyleManager
+      StyleManager,
+      TraitManager
     } = this.attributes;
     this.stopDefault();
     DomComponents.destroy();
@@ -791,6 +792,7 @@ export default Backbone.Model.extend({
     SelectorManager.destroy();
     StorageManager.destroy();
     StyleManager.destroy();
+    TraitManager.destroy();
     this.view.remove();
     this.stopListening();
     this.clear({ silent: true });

src/trait_manager/index.js

@@ -81,6 +81,11 @@ export default () => {
 
     render() {
       return TraitsViewer.render().el;
+    },
+
+    destroy() {
+      TraitsViewer.remove();
+      [c, TraitsViewer].forEach(i => (i = {}));
     }
   };
 };