Support NPM2 and Be React Version Agnostic 
> Remove peerDeps of reactcss: https://github.com/casesandberg/reactcss/blob/master/package.json#L73

> Publish a new reactcss version and use it in react-color.

> Move react-addons-shallow-compare from dep to devDep: https://github.com/casesandberg/react-color/blob/master/package.json#L43

> react-addons-shallow-compare would then also be an implicit dep for anyone using react-color.