Add support for non-EDU Tello Swarms using multiple WiFi dongles

[M4GNV5]

A user in the TelloPilot forum described a simple Swarm using regular Tellos. By binding a socket to a specific network device one can talk to multiple Tellos even though they have the same IP. This seems to be a somewhat better solution than the NAT solution discussed in #23.

We could add a new option interface=None to the Tello constructor similar to the host parameter. We currently have only one receiving socket for all Tello instances and might need multiple when supporting multiple interfaces.

Code snippet from the TelloPilot thread for reference:

#'wlxd03745aa6775' it will be different to your wifi dongle (check yours' using ifconfig command in Linux / Ubuntu OS).
drone_1 = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
drone_1.setsockopt(socket.SOL_SOCKET, 25, 'wlxd03745aa6775'.encode())
drone_2 = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
drone_2.setsockopt(socket.SOL_SOCKET, 25, 'wlxd03745ab21eb'.encode())