Rip out godotenv from configuration

Using environment variables for configuration is really nice for sys-admins and .env files is a nice way to write them all down.

Unfortunately, this means if your application depends on the configuration to be in a .env file, you have not really gained anything from leaving a YAML- or TOML-based config format. You just traded format.

Proposal: Replace godotenv dependency with straight up environment variables loading and move .env file loading to Docker and docker-compose.