code: function normalizeManifest(manifest, fn) {
    var obj = {};
    manifest.forEach(function(file) {
      if (!file) return;
      obj[file.name] = {
        mtime: file.mtime,
        mode: file.mode,
        size: file.size,
        hash: file.hash,
        link: file.link
      };
    });
    fn(null, obj);
  }
docs: Normalize the manifest into the expected format
  
  @param {Object} manifest
  @param {Function} fn