SDK does not support the Passenger object

[DoDSoftware]

Per the API docs at http://apiref.riskified.com/curl/#models-order, the Order model has a passengers property which should be

A list of passenger objects, each one containing information about a passenger in the order.

However, no PHP example is shown in the docs and in the php sdk, the Order model has no passengers field and there is no model for the Passenger object