Update dependency del to v5.1.0 (#498)

Author: renovate[bot]

package-lock.json

@@ -39,7 +39,7 @@
   "devDependencies": {
     "chalk": "2.4.2",
     "chromedriver": "75.1.0",
-    "del": "5.0.0",
+    "del": "5.1.0",
     "eslint": "6.1.0",
     "eslint-config-airbnb": "17.1.1",
     "eslint-plugin-import": "2.18.2",