UILabel 文字随机渐隐渐现，Swift 版 RQShineLabel

Swift实现的UILabel文字随机渐隐渐现, Swift版RQShineLabel. 暂时没做Pod和Carthage.

基础使用Demo：

    let blingBlingLabel = FNBlingBlingLabel.init(frame: CGRectMake(0, 0, 300, 200))
    blingBlingLabel.needAnimation = true
    blingBlingLabel.numberOfLines = 0
    blingBlingLabel.textColor = UIColor.whiteColor()
    blingBlingLabel.appearDuration = 1.5
    blingBlingLabel.disappearDuration = 1.5
    self.view.addSubview(blingBlingLabel)
    blingBlingLabel.text = "FNBlingBlingLabel-TestString"

效果：

来源：

OC原版是 RQShineLabel