UMD build is not enabled on UNPKG

[nickserv]

Visiting https://unpkg.com/react-redux displays the CJS build (https://unpkg.com/react-redux@5.0.7/lib/index.js) when the UMD build (https://unpkg.com/redux@4.0.0/dist/redux.js) should be displayed instead.

Please refer to the usage instructions at the bottom of https://unpkg.com/.

[timdorr]

Can you create a PR to add the unpkg field please?

[nickserv]

Sorry I didn't realize it was just a one line change, done! #1003