Update examples w/ cleaner serial code

[Poofjunior]

We can simplify connecting to a device in all the examples with:

import serial.tools.list_ports

# Open serial connection with the first Valve Controller.
com_port = None
ports = serial.tools.list_ports.comports()
for port, desc, hwid in sorted(ports):
    if desc.startswith("lickety-split"):
        print("{}: {} [{}]".format(port, desc, hwid))
        com_port = port
        break
device = Device(com_port)