Always run webpack in production mode. (#595)

Otherwise horribly inefficent code that evals(!) strings of code is generated.

package.json

@@ -37,8 +37,8 @@
   },
   "scripts": {
     "build": "npm run build-debug && npm run build-min",
-    "build-debug": "webpack --mode=development",
-    "build-min": "cross-env NODE_ENV=production webpack --mode=production",
+    "build-debug": "webpack",
+    "build-min": "cross-env NODE_ENV=production webpack",
     "build-watch": "webpack --watch",
     "test": "karma start --single-run",
     "prepublish": "npm run build"

webpack.config.js

@@ -12,6 +12,7 @@ Licensed MIT © Zeno Rocha`;
 
 module.exports = {
     entry: './src/clipboard.js',
+    mode: 'production',
     output: {
         filename: production ? 'clipboard.min.js' : 'clipboard.js',
         path: path.resolve(__dirname, 'dist'),
@@ -24,6 +25,7 @@ module.exports = {
         ]
     },
     optimization: {
+        minimize: production,
         minimizer: [
             new UglifyJSPlugin({
                 parallel: require('os').cpus().length,