Use module.exports syntax

[lbarasti]

No description provided.

[lbarasti]

This prevents the browser from complaining about unexpected token export in some settings - such us when running an app created via create-react-app

[coveralls]

Coverage remained the same at 100.0% when pulling 432bead on lbarasti:use-module-exports-syntax into 065dede on jmsmyth:master.

[jmsmyth]

Looks fine. Ideally I'd prefer to keep it using es modules, but its fine to switch to commonjs for now if it fixes things for you. I'm a bit surprised create-react-app doesn't support es modules already, but it could be because this module doesn't have the jsnext:main or module properties in its package.json..