fix: set webpack globalObject to "this" (#115)

Author: Sembauke

webpack.config.js

@@ -8,6 +8,7 @@ module.exports = {
   },
   devtool: process.env.NODE_ENV ? "source-map" : "inline-source-map",
   output: {
+    globalObject: 'this',
     library: {
       name: "helpers",
       type: "umd",