segue does not work in simple segue test
With this approach you should use modal segues. Push segue is a part of UINavigationController transitions
If you want to use push segue then you will need to put your testSegueViewcontroller into UINavigationController instance. This will allow the Push segue to work.
Push segue is a part of navigationcontroller if your viewcontroller is embed with uinavigation controller then only you will able to push the controller to another view. If you don't want to add navigation controller then use modal transitions.
You need to put the testSegueViewcontroller inside a UINavigationController.