fix(package): update @types/helmet to version 0.0.47

Closes #113

Author: greenkeeper[bot]

package.json

@@ -6,7 +6,7 @@
   "private": true,
   "dependencies": {
     "@types/body-parser": "^1.17.0",
-    "@types/helmet": "^0.0.42",
+    "@types/helmet": "^0.0.47",
     "bcryptjs": "^2.4.3",
     "body-parser": "^1.19.0",
     "debug": "^4.1.0",