fix(deps): update dependency google-auth-library to v4 (#422)

renovate[bot] · JustinBeckwith · commit e0a94afbc365 · 2019-05-09T15:48:09.000Z
diff --git a/package.json b/package.json
@@ -38,7 +38,7 @@
     "duplexify": "^3.6.0",
     "ent": "^2.2.0",
     "extend": "^3.0.2",
-    "google-auth-library": "^3.1.1",
+    "google-auth-library": "^4.0.0",
     "retry-request": "^4.0.0",
     "teeny-request": "^3.11.3"
   },
