Use `weak` for the ViewController in `InteractiveAnimator` to avoid retain cycle.
Use `weak` for the ViewController in `InteractiveAnimator` to avoid retain cycle.

JakeLin/IBAnimatable,alexiosdev/IBAnimatable,alexiosdev/IBAnimatable,IBAnimatable/IBAnimatable,seanwoodward/IBAnimatable,IBAnimatable/IBAnimatable,IBAnimatable/IBAnimatable,seanwoodward/IBAnimatable,JakeLin/IBAnimatable