Modernize with Hooks and Babel 7 (PR)

I have a PR (which is on lottie-react-web which is a fork of react-lottie) which is a rewrite with Hooks and Babel 7: felippenardi/lottie-react-web#17

Since both lottie-react-web and react-lottie aren't updated very often, I open to making my own official spin-off, but preferable I'd like to be a contributor to one of these upstream sources. 