Incompatible with YAML6.+

[tomvdp]

The open() method needs a Loader argument.
In configparser.py, get_configuration() has 2 open() calls that should be:
...
defaults = yaml.load(file, Loader=yaml.FullLoader)
...
user_config = yaml.load(file, Loader=yaml.FullLoader)

[sleiner]

Thanks you! :-)