Build the minified version in production mode

This is probably not the way to do this, I may want to just have
multiple versions, dev+production * full+min

createWebpackConfig.js

@@ -29,11 +29,24 @@ module.exports = function createWebpackConfig(_options) {
   config.output.filename = options.filename;
 
   if (options.minify) {
-    config.plugins.push(new webpack.optimize.UglifyJsPlugin({
-      compressor: {
-        screw_ie8: true,
-      },
-    }));
+    config.plugins.push(
+      new webpack.optimize.UglifyJsPlugin({
+        compressor: {
+          screw_ie8: true,
+          warnings: false,
+        },
+      })
+    );
+  }
+
+  if (options.env) {
+    config.plugins.push(
+      new webpack.DefinePlugin({
+        'process.env': {
+          NODE_ENV: JSON.stringify(options.env),
+        },
+      })
+    );
   }
 
   return config;

gulpfile.js

@@ -76,6 +76,7 @@ gulp.task('webpack:standalone:min', function() {
   var config = createWebpackConfig({
     filename: 'updeep-standalone.min.js',
     minify: true,
+    env: 'production',
   });
 
   return gulp.src('lib/index.js')