v3.1.4

◀️ Revert client.js bundles:
which caused in v3.1.3 in which changed to export default, since webpack 2.x resolve modules as commonjs, you may need to use window.WechatJSSDK.default or require('wechat-jssdk/dist/client').default in a non es module env in version 3.1.3, this version revert that back to module.exports, so you don't need the verbose .default

TODO: will upgrade webpack to 4 to solve the default issue