If config file contains non-empty dictionary for 'rename', function load_config in config.py throw exception of Schema validation error. ``` SchemaError: Key 'rename' error: Wrong keys '836d1983631e' in {'836d1983631e': 'room'} ``` Solution is to set in config.py key 'rename' to type of 'object' on https://github.com/hardwario/bch-gateway/blob/b274e77f435d7d2b4d2a520e1f7f12cf462db2e7/bcg/config.py#L49 to ``` Optional('rename'): object ``` as is mentioned at https://github.com/keleshev/schema#extra-keys