Integration of BME680 Sensor (#33)

Integrated the BME680 Sensor as Python module.

Performs a single read of temperature (°C), humidity (% r.h.), air pressure (hPa) and gas resistance (Ohm):

>>> import bme680
>>> bme680.get_bme_data()
(27.84, 28.452, 1022.72, 29021.0)