Add vinyl-source-stream to devDependencies
Add vinyl-source-stream to devDependencies

`require('vinyl-source-stream')` in gulpfile.js

https://github.com/na2hiro/json-kifu-format/blob/1046ebb435d265ae7a4014f29474643bebb6a7e6/gulpfile.js#L8

na2hiro/json-kifu-format,na2hiro/json-kifu-format,na2hiro/json-kifu-format