基本动画、位移动画、缩放动画、旋转动画、组动画、关键帧动画、贝塞尔曲线、进度条动画、复杂动画、UIView 类动画，UIview Block动画
1.CABasicAnimation;
2.CAKeyframeAnimation;
3.CATransition;
4.CASpringAnimation;
5.CAGradientLayer;
6.CAEmitter;
iOS动画 —— UIView动画 : https://www.jianshu.com/p/e39f6d6ed92b
iOS动画—— Core Animation: https://www.jianshu.com/p/62fae9546a8c
iOS动画 —— CATransition: https://www.jianshu.com/p/51948851c920
iOS动画 —— UIBezierPath：https://www.jianshu.com/p/fc5a1e0372fa
