message: Fix new jest.config.js behavior.
diff: @@ -35,13 +35,15 @@ const findConfig = (root: Path): InitialOptions => {
  const pkg = require(packageJsonFilePath);
  if (pkg.jest) {
  options = pkg.jest;
  - break;
  }
  + // Even if there is no configuration, we stop traveling up the
  + // tree if we hit a `package.json` file.
  + break;
  }
  } while (directory !== (directory = path.dirname(directory)));
  - if (!options.rootDir) {
  - options.rootDir = root;
  - }
  + options.rootDir = options.rootDir
  + ? path.resolve(root, options.rootDir)
  + : root;
  return options;
  };
  