func drawCircle(duration: Double, color: UIColor, clockwise: Bool) {
        let halfCircle: CGFloat = CGFloat(M_PI)
        let circle = CAShapeLayer()
        let rect: CGRect = CGRectMake(0, 0, 54.0, 54.0)
        let radius: CGFloat = rect.width/2



        circle.path = UIBezierPath(arcCenter: CGPointMake(rect.width/2, rect.height/2), radius: radius, startAngle: 0, endAngle: halfCircle*2, clockwise: true).CGPath
        circle.fillColor = UIColor.clearColor().CGColor
        circle.strokeColor = color.CGColor
        circle.lineWidth = 2


        let drawAnimation: CABasicAnimation = CABasicAnimation(keyPath: "strokeEnd")
        drawAnimation.duration = duration
        drawAnimation.repeatCount = 1.0

        drawAnimation.fromValue = NSNumber(float: 0)
        drawAnimation.toValue = NSNumber(float: 1)

        drawAnimation.timingFunction = CAMediaTimingFunction(name: kCAMediaTimingFunctionLinear)

        circle.addAnimation(drawAnimation, forKey: "drawCircleAnimation")


    }