The serve CLI doesn't exist yet, but we want nice tests for it when it
does exist.
Updates tailscale/corp#7515
Change-Id: Ib4c73d606242c4228f87410bbfd29bec52ca6c60
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
(I should've done this to start with.)
Updates tailscale/corp#7515
Change-Id: I7fb88cf95772790fd415ecf28fc52bde95507641
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>