code: function transformFiles(files, jsxhintOpts, jshintOpts, cb){
    return Promise.map(files, function(fileName) {
      return transformJSX(fileName, jsxhintOpts);
    })
    .then(function(filesContents) {
      debug("Successfully transformed %d files to JSX.", files.length);
  
      var tempFileNames = utils.createTempFiles(files, filesContents);
      debug("Moved %d files to temp directory at %s.", files.length, exports.tmpdir);
      // Create map of temp file names to original file names
      var fileNameMap = {};
      files.forEach(function(fileName, index){
        fileNameMap[tempFileNames[index]] = fileName;
      });
      return fileNameMap;
    })
    .nodeify(cb);
  }
docs: Transform a list of files from jsx. Calls back with a map relating
  the new files (temp files) to the old file names, e.g.
  {tempFile: originalFileName}
  
  @param  {Array}    files File paths to transform.
  @param  {Object}   jsxhintOpts        Options for JSXHint.
  @param  {Object}   jshintOpts         Options for JSHint.
  @param  {Function} cb    Callback.