add `easeOutBounce` to velocity.js

velocity.js

'use strict';
import Velocity from 'velocity-animate';

let baseEasings = {};

baseEasings.Bounce = p => {
  let pow2;
  let bounce = 4;
  while (p < ((pow2 = Math.pow(2, --bounce)) - 1) / 11) {}

  return 1 / Math.pow(4, 3 - bounce) - 7.5625 *
    Math.pow((pow2 * 3 - 2) / 22 - p, 2);
};

Velocity.Easings.easeOutBounce = p => 1 - baseEasings.Bounce(1 - p);

export default Velocity;