Process results_database parameters in config to format them for
    set database function

    :param dict config: project configuration dict
    :param str output_dir: output directory for results
    :return: string for db uri

def get_db_uri(config, output_dir):
    """Process results_database parameters in config to format them for
    set database function

    :param dict config: project configuration dict
    :param str output_dir: output directory for results
    :return: string for db uri
    """
    db_config = config.get("results_database", {"db_uri": "default"})
    if db_config['db_uri'] == 'default':
        return os.path.join(output_dir, "results.sqlite")
    return db_config['db_uri']