fix: plugins/google-cloud/package.json & plugins/google-cloud/.snyk to reduce vulnerabilities

The following vulnerabilities are fixed with a Snyk patch:
- https://snyk.io/vuln/SNYK-JS-HTTPSPROXYAGENT-469131

Author: snyk-bot

plugins/google-cloud/.snyk

@@ -34,3 +34,7 @@ patch:
         patched: '2019-10-04T05:12:08.723Z'
     - '@google-cloud/storage > gcs-resumable-upload > google-auth-library > gtoken > gaxios > https-proxy-agent':
         patched: '2019-10-04T05:12:08.723Z'
+    - snyk > proxy-agent > https-proxy-agent:
+        patched: '2019-10-05T07:58:30.881Z'
+    - snyk > proxy-agent > pac-proxy-agent > https-proxy-agent:
+        patched: '2019-10-05T07:58:30.881Z'

plugins/google-cloud/package.json

@@ -33,7 +33,7 @@
     "@google-cloud/storage": "3.2.1",
     "@verdaccio/commons-api": "^8.1.2",
     "@verdaccio/streams": "^8.1.2",
-    "snyk": "^1.230.5"
+    "snyk": "^1.231.0"
   },
   "devDependencies": {
     "@verdaccio/babel-preset": "^8.1.2",