PropTypes via the main React package is deprecated

Hello, In 3.3.0, in SelectRowHeaderColumn proptypes defined as

SelectRowHeaderColumn.propTypes = {
  children: _react.PropTypes.node,
  rowCount: _react.PropTypes.number
};

It causes Deprecation warning on React:

Warning: Accessing PropTypes via the main React package is deprecated. Use the prop-types package from npm instead.

React recommends to use prop-types npm package: https://facebook.github.io/react/docs/typechecking-with-proptypes.html

[ofirgeller]

@AllenFang I think the dist files were not updated when v4.0.0-beta-6 (and 5) were commited. I checked and they still have React.PropTypes in them, you might not be seeing the warnings because you are running via a build system, but when I try depending on this commit I do get the warning.

[AllenFang]

It was fixed on v4.0.0-beta.5 and ETA may in the second or third week on June