heartbeatButtonAction.swift

func performHeartBeat(sender: UIButton) {
    let imageView = UIImageView(frame: self.heartButton.frame)
    imageView.image = UIImage(named: "heart_border")
    self.view.addSubview(imageView)
    
    UIView.animateWithDuration(0.5, animations: { () -> Void in
        imageView.transform = CGAffineTransformMakeScale(3,3)
        imageView.alpha = 0
        }) { (completed) -> Void in
            imageView.removeFromSuperview()
    }
}