Enter on add root folder will add folder

Renamed Root Folder js files

src/UI/AddSeries/RootFolders/RootFolderModel.js

@@ -0,0 +1,12 @@
+'use strict';
+define(
+    [
+        'backbone'
+    ], function (Backbone) {
+        return Backbone.Model.extend({
+            urlRoot : window.NzbDrone.ApiRoot + '/rootfolder',
+            defaults: {
+                freeSpace: 0
+            }
+        });
+    });