0.2.1 release
- add bool setBusResolution(bits)
- add bool setBusSamples(value)
- add bool setShuntResolution(bits)
- add bool setShuntSamples(value)
- improve error checking several functions
- calls to writeRegister() should return 0.
- error handling needs improvement, this is a first step.
- improve INA219_get_settings.ino
- update keywords.txt
- update readme.md