This release includes:
* Moved adafruit_sgp40.py to adafruit_sgp40/__init__.py
* Added voc algorithm converted by Dfrobot
* Added index example
* Updated readme with usage example
* Added import of const() for use with blinka
* Added note about 1 hertz sample rate for algorithm
* Fixed examples to follow 1 hertz sample rate.
Thanks AVanVlack!
To use in CircuitPython, simply install the [Adafruit CircuitPython bundle](https://circuitpython.org/libraries).
To use in CPython, `pip3 install adafruit-circuitpython-sgp40`.
Read the [docs](http://circuitpython.readthedocs.io/projects/sgp40/en/latest/) for info on how to use it.