Polyfill for ChildNode.remove()

Hi @bebraw, I've just run in to some errors with IE. They are a result of IE9+ not implementing `ChildNode.remove()`. This results in an error being thrown whenever the `cleanup()` method is called from reactabular-resizable.

There is a polyfill on the [MDN docs](https://developer.mozilla.org/en-US/docs/Web/API/ChildNode/remove). Are you happy for it to be implemented in this package? I can help if needed.

Start by locating the cleanup() method used by reactabular-resizable and identify where ChildNode.remove() is called. Review the MDN ChildNode.remove() polyfill, then verify that cleanup() no longer throws in IE9+ and that existing behavior remains unchanged.

Written by the indexing model from the issue text.