Update a trip by admin

Trip field values to update, keyed by field. Only the keys you send are changed; omitted keys keep their stored value. Keys are your company's trip-field keys — discover them with GET /trip-fields; they are per-company and must not be copied from an example.

Stops of a multi-destination trip to update in the same edit: their dates and their own answers. A date change re-approves the trip like any date change.