segueForUnwindingToViewController no longer works

[ArthurClemens]

segueForUnwindingToViewController is deprecated.

Deprecation Statement
Use unwindForSegue:towardsViewController: instead.

[ArthurClemens]

Replace the function with:

override func unwindForSegue(unwindSegue: UIStoryboardSegue,
                               towardsViewController subsequentVC: UIViewController) {
    let segue = unwindSegue as! CustomUnwindSegue
    segue.animationType = .Push
}