Do not use a hard-coded default home location for drone_delivery
Do not use a hard-coded default home location for drone_delivery

Wait for the vehicle to supply us with a location before starting
the web server

Fixes #362

diydrones/dronekit-python,diydrones/dronekit-python,hamishwillee/dronekit-python,hamishwillee/dronekit-python,dronekit/dronekit-python,dronekit/dronekit-python