Add missing dependencies

flaskbb/themes/aurora/package.json

@@ -10,8 +10,10 @@
     "gulp": "^3.8.11",
     "gulp-bower": "0.0.11",
     "gulp-concat": "~2.4.2",
+    "gulp-minify-css": "^1.2.2",
     "gulp-notify": "^2.0.1",
+    "gulp-rename": "^1.2.2",
     "gulp-ruby-sass": "^2.0.6",
-    "gulp-uglify": "~1.0.1",
+    "gulp-uglify": "~1.0.1"
   }
 }