Trying to include needed polyfills into the build

.babelrc

@@ -1,5 +1,13 @@
 {
-  "presets": ["env"],
+  "presets": [["env", {
+    "useBuiltIns": true,
+    "modules": "umd",
+    "targets": {
+      "ie": "8",
+      "browsers": ">2%"
+    },
+    "debug": true
+  }]],
   "plugins": [
     "add-module-exports"
   ],

package-lock.json

@@ -7578,7 +7578,7 @@
       "dev": true,
       "requires": {
         "babel-runtime": "6.26.0",
-        "core-js": "2.5.3",
+        "core-js": "2.5.7",
         "regenerator-runtime": "0.10.5"
       },
       "dependencies": {
@@ -7588,7 +7588,7 @@
           "integrity": "sha1-llxwWGaOgrVde/4E/yM3vItWR/4=",
           "dev": true,
           "requires": {
-            "core-js": "2.5.3",
+            "core-js": "2.5.7",
             "regenerator-runtime": "0.11.1"
           },
           "dependencies": {
@@ -7601,9 +7601,9 @@
           }
         },
         "core-js": {
-          "version": "2.5.3",
-          "resolved": "https://registry.npmjs.org/core-js/-/core-js-2.5.3.tgz",
-          "integrity": "sha1-isw4NFgk8W2DZbfJtCWRaOjtYD4=",
+          "version": "2.5.7",
+          "resolved": "https://registry.npmjs.org/core-js/-/core-js-2.5.7.tgz",
+          "integrity": "sha512-RszJCAxg/PP6uzXVXL6BsxSXx/B05oJAQ2vkJRjyjrEcNVycaqOmNb5OTxZPE3xa5gwZduqza6L9JOCenh/Ecw==",
           "dev": true
         },
         "regenerator-runtime": {

package.json

@@ -33,6 +33,7 @@
     "babel-loader": "^7.1.5",
     "babel-plugin-add-module-exports": "^0.3.1",
     "babel-plugin-istanbul": "^4.1.6",
+    "babel-polyfill": "^6.26.0",
     "babel-preset-env": "^1.7.0",
     "babel-register": "^6.26.0",
     "coveralls": "^3.0.2",

webpack.config.js

@@ -3,7 +3,7 @@ const path = require('path');
 module.exports = {
   mode: 'production', // "production" | "development" | "none"
   // Chosen mode tells webpack to use its built-in optimizations accordingly.
-  entry: './src/bowser.js', // string | object | array
+  entry: ['./src/bowser.js'], // string | object | array
   // defaults to ./src
   // Here the application starts executing
   // and webpack starts bundling