update NodeGroup

src/NodeGroup/index.js

@@ -1,5 +1,4 @@
 import React, { Component } from 'react'
-import { polyfill } from 'react-lifecycles-compat'
 import PropTypes from 'prop-types'
 import { BaseNode, interval } from 'kapellmeister'
 import mergeKeys from '../core/mergeKeys'
@@ -234,7 +233,5 @@ NodeGroup.defaultProps = {
   interpolation: numeric,
 }
 
-polyfill(NodeGroup)
-
 export default NodeGroup