Upgrade to Webpack 4

examples/webpack/webpack.config.js

@@ -7,17 +7,10 @@ module.exports = {
     'main': './main.js',
     'pdf.worker': 'pdfjs-dist/build/pdf.worker.entry'
   },
+  mode: 'none',
   output: {
     path: path.join(__dirname, '../../build/webpack'),
     publicPath: '../../build/webpack/',
     filename: '[name].bundle.js'
-  },
-  plugins: [
-    new webpack.optimize.UglifyJsPlugin({
-      compressor: {
-        screw_ie8: true,
-        warnings: false
-      }
-    })
-  ]
+  }
 };