Ensure compatibility with Internet Explorer

We need to include babel-polyfill in our application as older versions
of Internet Explorer are not capable of the latest EcmaScript features
and functionality.

facebook/react#8379
https://babeljs.io/docs/en/babel-polyfill.html

package.json

@@ -9,6 +9,7 @@
     "test": "node_modules/.bin/mocha --require babel-core/register --recursive"
   },
   "dependencies": {
+    "babel-polyfill": "6.26.0",
     "body-parser": "1.18.2",
     "busboy": "0.2.14",
     "express": "4.16.2",

src/main.js

@@ -3,6 +3,7 @@
  * See license text in LICENSE.txt or at https://opensource.dbc.dk/licenses/gpl-3.0/
  */
 
+import "babel-polyfill";
 import React from "react";
 import ReactDOM from "react-dom";
 

webpack.common.js

@@ -6,7 +6,10 @@
 const path = require("path");
 
 module.exports = {
-    entry: path.resolve(__dirname, "src", "main.js"),
+    entry: [
+        'babel-polyfill',
+        path.resolve(__dirname, "src", "main.js")
+    ],
     output: {
         path: path.resolve(__dirname, "src", "static", "js"),
         filename: "bundle.js"

yarn.lock

@@ -606,7 +606,7 @@ babel-plugin-transform-strict-mode@^6.24.1:
     babel-runtime "^6.22.0"
     babel-types "^6.24.1"
 
-babel-polyfill@^6.26.0:
+babel-polyfill@6.26.0, babel-polyfill@^6.26.0:
   version "6.26.0"
   resolved "https://registry.yarnpkg.com/babel-polyfill/-/babel-polyfill-6.26.0.tgz#379937abc67d7895970adc621f284cd966cf2153"
   dependencies: