Remove stop kwarg and use write_then_readinto.

[tannewt]

See adafruit/circuitpython#2082 for details.

[caternuson]

I will test.

[caternuson]

Hmmm. So in testing this I think I've found another potential bug. A station with less than 8 characters does not get updated for some reason. This is happening with the current master and with this PR code. There's probably some basic issue with how the I2C comms are working which will take some datasheet reading and further testing.

This PR code works as well as current master. So two options:

1. merge this with TODOs left in, and open a new issue for the above
2. don't merge this, open a new issue for above that also includes updating for kwarg change (so two birds with one PR)

I'm leaning toward 1. Thoughts?

[ladyada]

not worth spending time on, this chip is about to be discontinued anyhow. plz go with #1

[caternuson]

cool, thanks. will do that...

[caternuson]

tested

import board, digitalio, adafruit_si4713
si_reset = digitalio.DigitalInOut(board.D10)
si4713 = adafruit_si4713.SI4713(board.I2C(), reset=si_reset, timeout_s=0.5)
si4713.tx_frequency_khz = 87500
si4713.tx_power = 115
si4713.configure_rds(0xADAF, station=b'IAMPR8:)', rds_buffer=b'boots and pants')