Support Storybook 4

[jantimon]

Hi

using this plugin with Storybook 4 causes the following issue (maybe it's because object hash and webpack 4)

object_hash.js:formatted:1 Uncaught TypeError: Cannot read property 'crypto' of undefined
    at object_hash.js:formatted:1
    at Object.<anonymous> (object_hash.js:formatted:1)
    at Object.7.buffer (object_hash.js:formatted:1)
    at o (object_hash.js:formatted:1)
    at object_hash.js:formatted:1
    at Object.<anonymous> (object_hash.js:formatted:1)
    at Object.5../md5 (object_hash.js:formatted:1)
    at o (object_hash.js:formatted:1)
    at object_hash.js:formatted:1
    at Object.<anonymous> (object_hash.js:formatted:1)
(anonymous) @ object_hash.js:formatted:1
(anonymous) @ object_hash.js:formatted:1
7.buffer @ object_hash.js:formatted:1
o @ object_hash.js:formatted:1
(anonymous) @ object_hash.js:formatted:1
(anonymous) @ object_hash.js:formatted:1
5../md5 @ object_hash.js:formatted:1
o @ object_hash.js:formatted:1
(anonymous) @ object_hash.js:formatted:1
(anonymous) @ object_hash.js:formatted:1
1.buffer @ object_hash.js:formatted:1
o @ object_hash.js:formatted:1
e @ object_hash.js:formatted:1
(anonymous) @ object_hash.js:formatted:1
../../../../../node_modules/object-hash/dist/object_hash.js @ object_hash.js:formatted:1
../../../../../node_modules/object-hash/dist/object_hash.js @ object_hash.js:formatted:1
__webpack_require__ @ object_hash.js:formatted:1
fn @ object_hash.js:formatted:1
../../../../../node_modules/react-storybook-addon-props-combinations/dist/index.js @ object_hash.js:formatted:1
__webpack_require__ @ object_hash.js:formatted:1
fn @ object_hash.js:formatted:1
./.storybook/addons.js @ object_hash.js:formatted:1
__webpack_require__ @ object_hash.js:formatted:1
fn @ object_hash.js:formatted:1
0 @ object_hash.js:formatted:1
__webpack_require__ @ object_hash.js:formatted:1
../../../../../node_modules/@storybook/addon-actions/dist/components/ActionLogger/index.js.Object.defineProperty.value @ object_hash.js:formatted:1
(anonymous) @ object_hash.js:formatted:1

Minimal code to reproduce:

import { setDefaults } from 'react-storybook-addon-props-combinations'

setDefaults({
  // overwrite global defaults here
})