Allow CareFactory fallback to default vehicleType
As written, the code would set a defualt type on the VehicleFactory prototype but *would not ever use it* because it was overridden in the constructor. This also made switching the default value to Truck in truck factory pointless, as the constructer overrode this as well
Merge pull request #138 from Sequoia/bug-vehicleClass-defaults

Allow CareFactory fallback to default vehicleType