chore(deps): update dependency typescript to v4.0.3 (GoogleCloudPlatform#221)

Co-authored-by: Huy Pham <[email protected]>

Author: renovate-bot

package-lock.json

@@ -46,6 +46,6 @@
     "mocha": "8.1.3",
     "power-assert": "1.6.1",
     "supertest": "4.0.2",
-    "typescript": "4.0.2"
+    "typescript": "4.0.3"
   }
 }