code: async function getReadersUuids(channelName, paths) {
      paths = paths || getPaths(channelName);
      const readersPath = paths.readers;
      const files = await readdir(readersPath);
  
      return files
          .map(file => file.split('.'))
          .filter(split => split[1] === 'json') // do not scan .socket-files
          .map(split => split[0]);
  }
docs: returns the uuids of all readers
  @return {string[]}