code: def clean(config):
      
      if not exists(config):
          logger.debug("Wily cache does not exist, skipping")
          return
      shutil.rmtree(config.cache_path)
      logger.debug("Deleted wily cache")
docs: Delete a wily cache.
  
      :param config: The configuration
      :type  config: :class:`wily.config.WilyConfig`