Swipe handling doesn't take velocity into account

[JoeSzymanski]

When swiping, the pan gesture recognizer doesn't account for the velocity of the swipe when the gesture completes. This means that a short flick, which feels like it should send the card off-screen, moves the card slightly and returns it back to the center.

This should be a relatively simple process of passing the pan gesture recognizer to the finalization method so that the velocity can be accessed and processed.