Add uglify to targets

Author: Timer

packages/babel-preset-react-app/index.js

@@ -86,8 +86,11 @@ if (env === 'test') {
       // Latest stable ECMAScript features
       [require.resolve('babel-preset-env'), {
         targets: {
-          // We support everything React supports
-          'ie': 9
+          // React parses on ie 9, so we should too
+          ie: 9,
+          // We currently minify with uglify
+          // Remove after https://github.com/mishoo/UglifyJS2/issues/448
+          uglify: true
         },
         // Disable polyfill transforms
         useBuiltIns: false