Provide an aggregate tests runner. See #4583

Provide an aggregate tests runner.
See: #4583
http://codeception.com/docs/08-Customization#One-Runner-for-Multiple-Applications
till this issue is not fixed (
* https://github.com/yiisoft/yii2/issues/4583#issuecomment-51032645
* https://github.com/Codeception/Codeception/issues/1057
), I dont see the need for applying this pull.