async function cleanFiles(platform, vol) {
  if (platform.files) {
    return Promise.all(
      platform.files.map((file) => {
        if (file.format) {
          return cleanFile(file, platform, vol);
        } else {
          throw new Error('Please supply a format');
        }
      }),
    );
  }
}
Takes a platform config object and a dictionary
object and cleans all the files. Dictionary object
should have been transformed and resolved before this
point.
@memberOf StyleDictionary
@param {PlatformConfig} platform
@param {Volume} [vol]