fix: allow usage with latest react-router version
fix: allow usage with latest react-router version

`react-router-dom@5` is supposed to be totally backwards compatible. The only breaking
change I've noticed is if you access its context directly and I don't think that's done
anywhere in this repo. I think that was kind of a hidden feature we weren't "supposed" to be
using anyway.
svenanders/react-breadcrumbs,svenanders/react-breadcrumbs