Remove reference to `routeTo`

routeTo is likely not going to survive the router facelift. It was experimental,
and is still is on the ENV.ENABLE_ROUTE_TO flag, which wasn't mentioned in this
blog, but given that it likely won't stick around, I'd rather remove it than
clarify about the flag.
Merge pull request #540 from machty/patch-1

Remove reference to `routeTo`