Update SPI Examples

CS can be on any GPIO pin. Board.CE0 is a poor choice in the examples. Updated examples to use D20 instead, with a comment that any available GPIO pin can be used.

Reverted code to read registers

The write_then_readinto() function does not appear to reliably read the registers. Revert the change to Write & Read Register using write_then_readinto back to an explicit write() followed by a readinto().

Minor Fix to Write & Read Register I2C Logic

Changed the I2C logic to use write_then_readinto() function, rather than a write() followed by read().

Update Build and Minor Fixes

Updated code with some minor fixes for some issues and updated the build process to the new Adafruit build process.

CircuitPython Community release

Updated the tune_cap property to return and set the tuning capacitor value in pF.

Third clean build attempt

Fixed issue with examples.rst doc file

Second clean build attempt

Second attempt for a pylint free build.

First build attempt

First travis build attempt