Update nest monorepo to v6

Author: renovate-bot

integration/hello-world/package-lock.json

@@ -7,11 +7,11 @@
     "start": "ts-node src/main"
   },
   "dependencies": {
-    "@nestjs/common": "5.7.4",
-    "@nestjs/core": "5.7.4",
-    "@nestjs/microservices": "5.7.4",
-    "@nestjs/testing": "5.7.4",
-    "@nestjs/websockets": "5.7.4",
+    "@nestjs/common": "6.0.1",
+    "@nestjs/core": "6.0.1",
+    "@nestjs/microservices": "6.0.1",
+    "@nestjs/testing": "6.0.1",
+    "@nestjs/websockets": "6.0.1",
     "class-transformer": "0.2.0",
     "class-validator": "0.9.1",
     "fastify": "2.1.0",