message: cleanup of cruft
diff: /**
  * Postprocess step. Stolen from babel-jest: https://github.com/facebook/jest/blob/master/packages/babel-jest/src/index.js
  */
  -
  -import * as crypto from 'crypto';
  -import * as fs from 'fs';
  -import * as path from 'path';
  import * as jestPreset from 'babel-preset-jest';
  import { JestConfig, PostProcessorOptions, TransformOptions } from './jest-types';
  import * as babel from 'babel-core';
  -const BABELRC_FILENAME = '.babelrc';
  -const BABELRC_JS_FILENAME = '.babelrc.js';
  -const BABEL_CONFIG_KEY = 'babel';
  -const PACKAGE_JSON = 'package.json';
  -//const THIS_FILE = fs.readFileSync(__filename);
  -
  -let babel;
  export const createTransformer = (options: PostProcessorOptions) => {
  - /*const getBabelRC = filename => {
  - const paths = [];
  - let directory = filename;
  - while (directory !== (directory = path.dirname(directory))) {
  - if (cache[directory]) {
  - break;
  - }
  -
  - paths.push(directory);
  - const configFilePath = path.join(directory, BABELRC_FILENAME);
  - if (fs.existsSync(configFilePath)) {
  - cache[directory] = fs.readFileSync(configFilePath, 'utf8');
  - break;
  - }
  - const configJsFilePath = path.join(directory, BABELRC_JS_FILENAME);
  - if (fs.existsSync(configJsFilePath)) {
  - // $FlowFixMe
  - cache[directory] = JSON.stringify(require(configJsFilePath));
  - break;
  - }
  - const packageJsonFilePath = path.join(directory, PACKAGE_JSON);
  - if (fs.existsSync(packageJsonFilePath)) {
  - // $FlowFixMe
  - const packageJsonFileContents = require(packageJsonFilePath);
  - if (packageJsonFileContents[BABEL_CONFIG_KEY]) {
  - cache[directory] = JSON.stringify(
  - packageJsonFileContents[BABEL_CONFIG_KEY],
  - );
  - break;
  - }
  - }
  - }
  - paths.forEach(directoryPath => (cache[directoryPath] = cache[directory]));
  - return cache[directory] || '';
  - };*/
  - options = Object.assign({}, options, {
  + options = {...options,
  plugins: (options && options.plugins) || [],
  presets: ((options && options.presets) || []).concat([jestPreset]),
  retainLines: true,
  - });
  + };
  delete options.cacheDirectory;
  delete options.filename;
  return {
  canInstrument: true,
  - /*getCacheKey(fileData: string,
  - filename: Path,
  - configString: string,
  - {instrument}: TransformOptions,): string {
  - return crypto
  - .createHash('md5')
  - .update(THIS_FILE)
  - .update('\0', 'utf8')
  - .update(fileData)
  - .update('\0', 'utf8')
  - .update(configString)
  - .update('\0', 'utf8')
  - .update(getBabelRC(filename))
  - .update('\0', 'utf8')
  - .update(instrument ? 'instrument' : '')
  - .digest('hex');
  - },*/
  process(src: string,
  filename : string,
  config : JestConfig,
  