We missed this because Flow wasn't being run properly on Travis but now that it is, it's clear that #7716 introduced a bunch of new Flow failures. Most of these shouldn't be too bad and I like to say "you break it you buy it" so this one is for you @Aweary :)

There were a couple other pre-existing Flow issues that @vjeux is going to fix, so mostly this should just be the TestRenderer issues.

/**
 * Copyright 2013-present, Facebook, Inc.
 * All rights reserved.
 *
 * This source code is licensed under the BSD-style license found in the
 * LICENSE file in the root directory of this source tree. An additional grant
 * of patent rights can be found in the PATENTS file in the same directory.
 *
 * @providesModule ReactTestEmptyComponent
 * @flow
 */
'use strict';
class ReactTestEmptyComponent {
  constructor() {
    this._currentElement = null;
  }
  receiveComponent(): void {}
  toJSON(): void {}
  mountComponent(): void {}
  getHostNode(): void {}
  unmountComponent(): void {}
}
module.exports = ReactTestEmptyComponent;