class RuboCop::ConfigLoader

there either, the path to the default file is returned.
user's home directory is checked. If there's no .rubocop.yml
inspected file is. If no .rubocop.yml is found there, the
directory structure starting at the given directory where the
Returns the path of .rubocop.yml searching upwards in the

def configuration_file_for(target_dir)
  config_files_in_path(target_dir).first || DEFAULT_FILE
end