react should be peerDependancy

[dpwrussell]

As it stands, react-range depends on react which can introduce a different version of React and thus to:

Uncaught Error: Invariant Violation: Modal.render(): A valid ReactComponent must be returned. You may have returned undefined, an array or some other invalid object.

It can be fixed temporarily by deleting node_modules/react-range/node_modules/react. I think the standard way of handling this is to make it a peer dependancy.

[damienleroux]

I made a pull request: #20.

I'll be thankful to have it accepted please.

Thank you :)

[dasulit]

Mapbox is no longer maintaining react-range. For a current alternative, check out https://mapbox.github.io/mr-ui/#controlrange.