chore(deps): update dependency firebase-functions-test to v3

Author: renovate[bot]

functions/package.json

@@ -32,7 +32,7 @@
   "devDependencies": {
     "eslint": "^6.8.0",
     "eslint-plugin-promise": "^4.3.1",
-    "firebase-functions-test": "^0.3.3"
+    "firebase-functions-test": "^3.4.0"
   },
   "private": true
 }