try fixing react warnings again

webpack.config.js

@@ -1,13 +1,22 @@
-const path = 'path'
+const path = require('path')
-const webpack = 'webpack'
+const webpack = require('webpack')
+
+const NODE_ENV = process.env.NODE_ENV || 'development'
+
+const plugins = [
+  new webpack.DefinePlugin({
+    "process.env.NODE_ENV": `"${NODE_ENV}"`
+  })
+]
+if (NODE_ENV === 'production') {
+  plugins.push(new webpack.optimize.UglifyJsPlugin({
+    compress: { warnings: false }
+  }))
+}
 
 const config = module.exports = {
   context: __dirname,
-  plugins: [
+  plugins,
-    new webpack.DefinePlugin({
-      "process.env.NODE_ENV": `"${process.env.NODE_ENV || 'development'}"`
-    })
-  ],
   module: {
     loaders: [
       {