config parameters as enviroment variables

[DanielWeeber]

parameters for /usr/local/homematic_exporter (esp. "ccu_host") should be configurable via enviroment variables

would be better/easier/more usual for running as a docker

[sfudeus]

Agreed - unfortunately the Python library I am using does not have support for initializing cli args based on environment variables. Setting defaults from env would have the drawback of losing the explicit definition of required arguments.