chore(package): update del to version 4.1.0

Author: greenkeeper[bot]

package.json

@@ -38,7 +38,7 @@
   "devDependencies": {
     "@babel/core": "7.4.0",
     "@babel/preset-env": "7.4.1",
-    "del": "4.0.0",
+    "del": "4.1.0",
     "eslint": "5.16.0",
     "eslint-config-google": "0.12.0",
     "gulp": "4.0.0",