code: def _get_config_files():
      
      config_paths = []
      if os.environ.get('FEDMSG_CONFIG'):
          config_location = os.environ['FEDMSG_CONFIG']
      else:
          config_location = '/etc/fedmsg.d'
  
      if os.path.isfile(config_location):
          config_paths.append(config_location)
      elif os.path.isdir(config_location):
          # list dir and add valid files
          possible_config_files = [os.path.join(config_location, p)
                                   for p in os.listdir(config_location) if p.endswith('.py')]
          for p in possible_config_files:
              if os.path.isfile(p):
                  config_paths.append(p)
      if not config_paths:
          _log.info('No configuration files found in %s', config_location)
      return config_paths
docs: Load the list of file paths for fedmsg configuration files.
  
      Returns:
          list: List of files containing fedmsg configuration.