版本：
文件：
- https://cdn.bootcdn.net/ajax/libs/eventsource-polyfill/0.9.6/browserify-eventsource.js
- https://cdn.bootcdn.net/ajax/libs/eventsource-polyfill/0.9.6/browserify-eventsource.min.js
- https://cdn.bootcdn.net/ajax/libs/eventsource-polyfill/0.9.6/eventsource.js
- https://cdn.bootcdn.net/ajax/libs/eventsource-polyfill/0.9.6/eventsource.min.js