ライセンス

・firebase

https://github.com/firebase/firebase-js-sdk/blob/firebase%407.5.2/LICENSE

・CocosCreator

Copyright (c) 2013-2016 Chukong Technologies Inc.
Copyright (c) 2017-2018 Xiamen Yaji Software Co., Ltd.
https://github.com/cocos-creator/engine/blob/master/licenses/LICENSE