fix test

lib/src/commands/LayoutTreeParser.test.js

 
   describe('createContainer', () => {
     it('creates container object with passed data', () => {
-      expect(uut._createContainer({ foo: 'bar' })).toEqual({ type: 'Container', data: { foo: 'bar' }, children: [] });
+      expect(uut.parseFromSimpleJSON({ name: 'theContainer', foo: 'bar' })).toEqual({ type: 'Container', data: { name: 'theContainer', foo: 'bar' }, children: [] });
     });
   });