Merge pull request #55 from LeetCode-OpenSource/greenkeeper/lint-staged-9.0.0

Update lint-staged to the latest version 🚀

Author: Brooooooklyn

package.json

@@ -34,7 +34,7 @@
     "html-webpack-plugin": "^3.2.0",
     "husky": "^2.3.0",
     "jest": "^24.8.0",
-    "lint-staged": "^8.1.7",
+    "lint-staged": "^9.0.0",
     "prettier": "^1.17.1",
     "react": "16.8.6",
     "react-dom": "16.8.6",