Use uglify-js v2.5.0 to fix #52

package.json

@@ -62,7 +62,7 @@
     "gulp-shell": "^0.5.1",
     "gulp-sourcemaps": "^1.5.2",
     "gulp-tag-version": "^1.3.0",
-    "gulp-uglify": "^1.5.1",
+    "gulp-uglify": "1.4.*",
     "gulp-util": "^3.0.6",
     "gulp-watch": "^4.3.5",
     "minimist": "^1.2.0",