oneOfType Error

After fresh install of any one of the following versions tried, **v1.2.2**, **v1.2.1** & **v1.1.0**, I'm getting the following in console.

```
Uncaught TypeError: Cannot read property 'oneOfType' of undefined
at eval (BaseCollectionHelper.js?eabe:29)
at Object. (bundle.js:11178)
at __webpack_require__ (bundle.js:50)
at eval (index.js?ac6a:1)
at Object. (bundle.js:347)
at __webpack_require__ (bundle.js:50)
at eval (index.js?75c9:1)
at Object. (bundle.js:11171)
at __webpack_require__ (bundle.js:50)
at eval (AdminUsers.js?eec1:9)
```

In source file....

```
BaseCollectionHelper.propTypes = {
children: PropTypes.oneOfType([PropTypes.func, PropTypes.element]).isRequired, <----- This line...
elementType: PropTypes.oneOfType([PropTypes.string, // For native nodes (eg. 'div')
PropTypes.func]).isRequired,
collection: PropTypes.array.isRequired
};
```

Any ideas here of what's going on?

Reproduce the error after a fresh install of versions v1.2.2, v1.2.1, or v1.1.0, then inspect BaseCollectionHelper.js at line 29 and the PropTypes usage shown in the report. Done means the collection helper loads without the oneOfType runtime error and its existing prop-type declarations work as intended.

Written by the indexing model from the issue text.