Adafruit-circuitpython-bme680

This release allows you to disable the gas heater by passing `None` for either argument of `set_gas_heater()`. Thank you graeme-winter.

To use in CircuitPython, simply install the [Adafruit CircuitPython Bundle](https://circuitpython.org/libraries).

To use in CPython, `pip3 install adafruit-circuitpython-BME680`.

Read the [docs](http://circuitpython.readthedocs.io/projects/BME680/en/latest/) for info on how to use it.

This release contains a fix for the calculation of the gas resistence value. Thank you patcher-ms.

To use in CircuitPython, simply install the [Adafruit CircuitPython Bundle](https://circuitpython.org/libraries).

To use in CPython, `pip3 install adafruit-circuitpython-BME680`.

Read the [docs](http://circuitpython.readthedocs.io/projects/BME680/en/latest/) for info on how to use it.

This release adds functionality to set gas heater. Thank you garberw.

To use in CircuitPython, simply install the [Adafruit CircuitPython Bundle](https://circuitpython.org/libraries).

To use in CPython, `pip3 install adafruit-circuitpython-BME680`.

Read the [docs](http://circuitpython.readthedocs.io/projects/BME680/en/latest/) for info on how to use it.

To use in CircuitPython, simply install the [Adafruit CircuitPython Bundle](https://circuitpython.org/libraries).

To use in CPython, `pip3 install adafruit-circuitpython-BME680`.

Read the [docs](http://circuitpython.readthedocs.io/projects/BME680/en/latest/) for info on how to use it.

Update `pyproject.toml` to include the ability optional dependencies. Note that these are not currently used, but are intended to keep this libraries aligned with others in the Adafruit CircuitPython Bundle. Thanks tekktrik!

To use in CircuitPython, simply install the [Adafruit CircuitPython Bundle](https://circuitpython.org/libraries).

To use in CPython, `pip3 install adafruit-circuitpython-bme680`.

Read the [docs](http://circuitpython.readthedocs.io/projects/bme680/en/latest/) for info on how to use it.

To use in CircuitPython, simply install the [Adafruit CircuitPython Bundle](https://circuitpython.org/libraries).

To use in CPython, `pip3 install adafruit-circuitpython-bme680`.

Read the [docs](http://circuitpython.readthedocs.io/projects/bme680/en/latest/) for info on how to use it.