Update npm to the latest version 🚀 (#44)

* fix(package): update npm to version 6.11.0

* chore(package): update lockfile package-lock.json

Author: greenkeeper[bot]

package-lock.json

@@ -37,7 +37,7 @@
     "chalk": "~3.0.0",
     "changelog": "~1.4.2",
     "cli": "~1.0.1",
-    "npm": "~6.10.0",
+    "npm": "~6.11.0",
     "semver-compare": "~1.0.0"
   },
   "devDependencies": {