Update dependency @google-cloud/monitoring to v0.6.0 (#873)

Author: renovate[bot]

functions/log/package.json

@@ -18,7 +18,7 @@
   },
   "dependencies": {
     "@google-cloud/logging": "1.2.0",
-    "@google-cloud/monitoring": "0.4.1"
+    "@google-cloud/monitoring": "0.6.0"
   },
   "devDependencies": {
     "@google-cloud/nodejs-repo-tools": "^3.0.0",