This allows the test to be run inside a mounted filesystem,
which I'm doing now as a I develop on a linux VM.
Fixes#2367.
Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
On unix, we want to provide a full path to the desired unix socket.
On windows, currently we want to provide a TCP port, but someday
we'll also provide a "path-ish" object for a named pipe.
For now, simplify the API down to exactly a path and a TCP port.
Signed-off-by: David Anderson <dave@natulte.net>