async writeFileAsync({ dir, name, buffer }) {
    const filePath = this.getFilePath({ dir, name, prefix: false });
    const data = await fs.outputFile(filePath, buffer);
    return data;
  }
Write files asynchronously
@param {object} conf - processing configuration
@param {string} conf.dir - File directory
@param {string} conf.name - File directory
@param {string} conf.buffer - Original file name
@async
@public