chore(package): update lint-staged to version 4.0.0

Author: greenkeeper[bot]

package.json

@@ -29,7 +29,7 @@
     "grunt-contrib-clean": "^1.1.0",
     "grunt-contrib-nodeunit": "^1.0.0",
     "husky": "^0.13.3",
-    "lint-staged": "^3.4.0",
+    "lint-staged": "^4.0.0",
     "prettier": "^1.2.2",
     "standard-version": "^4.0.0"
   },