Integration with relay-tools/react-router-relay.

I like how this project reuses react-router, and I think this is the right direction for true code sharing between native apps and web.
I want to open an issue for integration with [react-router-relay](https://github.com/relay-tools/react-router-relay) as well.
I'm not sure if it would work out of box as is now, but I will play with it soon to see whether it needs some modifications.