chore: release 3.1.0 (#218)

Author: release-please[bot]

security-center/snippets/package.json

@@ -14,7 +14,7 @@
   "license": "Apache-2.0",
   "dependencies": {
     "@google-cloud/pubsub": "^1.5.0",
-    "@google-cloud/security-center": "^3.0.1"
+    "@google-cloud/security-center": "^3.1.0"
   },
   "devDependencies": {
     "chai": "^4.2.0",