Failure to read polarion_tools.yaml from base dir

When polarion_tools.yaml is placed at the base directory of the repository being validated, it is not read by polarion-tools-common.

The config file appears to only work when placed in conf/ directory within the validated repository.

Writing the issue here because the example yaml file is included in this repository, not polarion-tools-common, even though the configuration module/functions are in polarion-tools-common.