chore(package): update @types/helmet to version 0.0.45

Closes #45

Author: greenkeeper[bot]

package.json

@@ -21,7 +21,7 @@
     "@types/cors": "^2.8.3",
     "@types/dotenv": "^6.1.0",
     "@types/graphql": "^0.13.4",
-    "@types/helmet": "^0.0.42",
+    "@types/helmet": "^0.0.45",
     "@types/jest": "^23.3.9",
     "@types/supertest": "^2.0.6",
     "coveralls": "^3.0.0",