chore(deps): update dependency google/cloud-security-center to ^0.8.0 (GoogleCloudPlatform#1118)

Author: renovate-bot

securitycenter/composer.json

@@ -1,6 +1,6 @@
 {
     "require": {
-        "google/cloud-security-center": "^0.7.0",
+        "google/cloud-security-center": "^0.8.0",
         "google/cloud-pubsub": "^1.23.0"
     }
 }