0.03 - Sun Sep 20 17:44:12 2020
  * added official USA EPA guidelines for calculating AQI (PDF document)
  * added graphic depicting of PM2.5 to AQI correlation
  * modified:   lib/Weather/PurpleAir/API.pm:  Implemented conformant concentration_to_epa function

0.02 - Sun Sep 20 11:35:05 2020
  * Major refactor to make unit tests easier to write
  * Allow multiple sensors per report
  * Use current or ten-minute average concentration
  * Convert from raw concentration to EPA AQI metric (per PurpleAir map)
  * Pull all results from a sensor and show either each individually or their average
  * Provide a best guess from pruned average of multiple sensors
  * Only print results when asked (eg, when invoked from app vs using the module programmatically)
  * Wrote a unit test (needs a lot more)
  * Wrote some documentation
  * More features implemented

0.01 - Fri Sep 18 23:01:18 2020
  * Initialized repo from ~/bin/aqi throwaway script, split into module + wrapper app.
