Portal: Fix Invalid "style" PropType (#1664)

* Fix bad prop.

(cherry picked from commit 7d54ca0a30b6238195a9cfd6da19e8fa94655ae5)

* fix prop-type.

(cherry picked from commit f48a0e2881f6541e4acd4e9f7610bda629b0fcc8)

components/hoc/Portal.js

@@ -1,13 +1,14 @@
 import React, { Component } from 'react';
 import PropTypes from 'prop-types';
 import ReactDOM from 'react-dom';
+import styleShape from 'react-style-proptype';
 
 class Portal extends Component {
   static propTypes = {
     children: PropTypes.node,
     className: PropTypes.string,
     container: PropTypes.node,
-    style: PropTypes.style,
+    style: styleShape,
   }
 
   static defaultProps = {