react-router-component

The new API looks quite a bit like the API we've been running in React-Router-Component since 2014 (https://github.com/STRML/react-router-component). Of course, RRC is not as battle-tested as React-Router; it's more of a "works for us" project I took over from @andreypopp as we had already committed to the router before React-Router became stable. And given the many backcompat-breaking changes to React-Router, it seems to have been a good idea. React-Router does great work though; RRC doesn't even pretend to do React Native and the Environment selection we do have (pathname, pushstate, etc) isn't quite as nice. RRC also can't do some of the more interesting features, like Recursive Routes. All of the children of the router have to be `<Location>` objects. Edit: React-Router's docs are awesome! Nice work @ryanflorence.