generatePath is not exported from index.js

[JAndritsch]

Version

4.1.1

Test Case

https://codesandbox.io/s/jz97zr9z0v

Steps to reproduce

1. import { generatePath } from 'react-router';
2. Try to use generatePath

Expected Behavior

Importing generatePath from react-router gives me access to the generatePath function, which accepts a path template string and params and then returns a compiled path.

Actual Behavior

generatePath is undefined because it is not part of the main exports in index.js.

[pshrmn]

#5661