**Do you want to request a *feature* or report a *bug*?**

Report a bug.

**What is the current behavior?**

Adding a style object to an element with the `columns` shorthand property expand it the wrong way, it should be left untouched.
```
<div style={{ columns: 2 }}>
```
Expand to:
```
<div style="columns: auto 2px;">
```
Which is a totally different behaviour.
See: https://developer.mozilla.org/en-US/docs/Web/CSS/columns

**If the current behavior is a bug, please provide the steps to reproduce and if possible a minimal demo of the problem via https://jsfiddle.net or similar (template: https://jsfiddle.net/84v837e9/).**

https://codesandbox.io/s/YvYVjQZ9O

**What is the expected behavior?**
```
<div style="columns: 2;">
```


**Which versions of React, and which browser / OS are affected by this issue? Did this work in previous versions of React?**

Latest 15.6.1
/**
 * Copyright 2013-present, Facebook, Inc.
 * All rights reserved.
 *
 * This source code is licensed under the BSD-style license found in the
 * LICENSE file in the root directory of this source tree. An additional grant
 * of patent rights can be found in the PATENTS file in the same directory.
 *
 * @providesModule CSSProperty
 */
'use strict';
/**
 * CSS properties which accept numbers but are not in units of "px".
 */
var isUnitlessNumber = {
  animationIterationCount: true,
  borderImageOutset: true,
  borderImageSlice: true,
  borderImageWidth: true,
  boxFlex: true,
  boxFlexGroup: true,
  boxOrdinalGroup: true,
  columnCount: true,