code: function normalizeManifestPaths (tokensByFile, rootDir) {
    var output = {};
    var rootDirLength = rootDir.length + 1;
  
    Object.keys(tokensByFile).forEach(function (filename) {
      var normalizedFilename = filename.substr(rootDirLength);
      output[normalizedFilename] = tokensByFile[filename];
    });
  
    return output;
  }
docs: /*
  
  Normalize the manifest paths so that they are always relative
  to the project root directory.