chore(package): update del to version 4.1.1

Closes #37

Author: greenkeeper[bot]

package.json

@@ -39,7 +39,7 @@
     "@julmot/git-branch-deploy": "^1.0.0",
     "ajv": "^6.0.0",
     "cldr-data": "^34.0.0",
-    "del": "^3.0.0",
+    "del": "^4.1.1",
     "eslint": "^5.0.0",
     "glob": "^7.1.2",
     "simple-git": "^1.77.0",