message: fix(deps): upgrade module extend to fix CVE-2018-16492
  Upgrade module extend to fix CVE-2018-16492 Prototype pollution vulnerability
diff: "@types/long": "^4.0.0",
  "arrify": "^2.0.0",
  "async-each": "^1.0.1",
  - "extend": "^3.0.1",
  + "extend": "^3.0.2",
  "google-auth-library": "^3.0.0",
  "google-gax": "^1.0.0",
  "grpc": "1.21.1",
  