upgraded build tools

webpack.config.js

@@ -1,4 +1,5 @@
-var path = require('path');
+const path = require('path');
+const mode = process.argv.slice(-1)[0];
 
 module.exports = {
 	entry: {
@@ -10,13 +11,16 @@ module.exports = {
 		path: path.join(__dirname, 'public', 'js'),
 		filename: '[name].js'
 	},
-	devtool: 'inline-source-map',
+	devtool: mode === 'development' ? 'inline-source-map' : '',
 	module: {
 		rules: [
 			{
 				test: path.join(__dirname, 'src'),
 				use: {
-					loader: 'babel-loader'
+					loader: 'babel-loader',
+					options: {
+						presets: ['@babel/preset-env']
+					}
 				}
 			}
 		]