Support for different QOS settings

[Michael-Equi]

Are there currently any plans to provide easy access to the MQTT QOS settings through this library such as in https://github.com/adafruit/Adafruit_MQTT_Library? Thanks

[brentru]

@Michael-Equi I could add an argument to the feed publish functions. Something like counter->save(count, 1);

However, the Adafruit IO MQTT API supports QoS level 0 (at most once) and 1 (at least once) only.