Possibly wrap PySerial inside UART for linux systems

[dhalbert]

UART is missing:

• baudarte
• in_waiting
• timeout
• __enter__()
• __exit__()
• reset_input_buffer()

I don't actually need these on Blinka right now, but because Blinka is used by pylint to check methods and properties, I have to disable checking for these.

[makermelissa]

If you are referring to the UART class in busio, that is only used in MicroPython. We have been using PySerial for anything linux based.

[dhalbert]

Ah, OK, though it's still true that pylint uses these definitions to vet calls to UART. Perhaps this is overloading the function of Blinka.

Could you actually wrap PySerial inside busio.UART?

[makermelissa]

Hmm, that's not a bad idea. Then we wouldn't need people to change code for examples.