Reads have hydrated a booking's travellers since #1517; there was no way
to write them, so an imported booking could not record who was on it -
and creating a guest is only half an answer if the guest cannot then be
attached to the flight they were on.
Mirrors PUT /api/trips/:tripId/reservations/:id/travelers. The roster
filter stays in the service, so an off-trip id is dropped rather than
attached and the tool cannot be used to enumerate users.
Maurice
86c0c197db