Allow the react component animation duration to be configurable

Currently, the animation duration in our react component is set at `200ms`. This is hardcoded. It would be great if the duration could be broken out into a property that could be customized by the user.
- Add a property for `animation in length` and `animation out length`
- Give them a default value of `200ms` by adding to the property default values [here](https://github.com/1egoman/funnies/blob/master/src/react.js#L96).

Thanks!