fix(uglify) - rollback uglify

package.json

@@ -31,7 +31,7 @@
     "gulp-shell": "^0.5.2",
     "gulp-size": "~2.1.0",
     "gulp-sourcemaps": "~1.9.1",
-    "gulp-uglify": "~2.0.0",
+    "gulp-uglify": "~1.4.1",
     "gulp-useref": "~1.3.0",
     "gulp-util": "~3.0.6",
     "gulp-zip": "^3.0.2",