fix: pin lint-staged to 9.2.3

Author: greenkeeper[bot]

package.json

@@ -34,7 +34,7 @@
     "html-webpack-plugin": "^3.2.0",
     "husky": "^3.0.3",
     "jest": "^24.8.0",
-    "lint-staged": "^9.0.0",
+    "lint-staged": "9.2.3",
     "prettier": "^1.17.1",
     "react": "16.9.0",
     "react-dom": "16.9.0",