chore(package): update helmet to version 3.22.0

Closes #16

Author: greenkeeper[bot]

package.json

@@ -47,7 +47,7 @@
     "eslint": "3.19.0",
     "eslint-config-fullcube": "2.0.2",
     "faker": "4.1.0",
-    "helmet": "3.6.1",
+    "helmet": "3.22.0",
     "loglevel": "1.4.1",
     "loopback": "3.8.0",
     "loopback-boot": "2.24.0",