Bump firebase-functions from 2.2.1 to 2.3.0 in /functions (#75)

Bumps [firebase-functions](https://github.com/firebase/firebase-functions) from 2.2.1 to 2.3.0.
- [Release notes](https://github.com/firebase/firebase-functions/releases)
- [Changelog](https://github.com/firebase/firebase-functions/blob/master/changelog.txt)
- [Commits](firebase/firebase-functions@v2.2.1...v2.3.0)

Signed-off-by: dependabot[bot] <support@dependabot.com>

functions/package.json

@@ -20,7 +20,7 @@
  "@types/node-fetch": "^2.3.2",
  "actions-on-google": "^2.6.0",
  "firebase-admin": "^7.3.0",
- "firebase-functions": "^2.2.1",
+ "firebase-functions": "^2.3.0",
  "node-fetch": "^2.3.0",
  "tape": "^4.10.1"
  },

functions/yarn.lock

@@ -1044,10 +1044,10 @@ firebase-admin@^7.3.0:
  "@google-cloud/firestore" "^1.2.0"
  "@google-cloud/storage" "^2.3.0"
 
-firebase-functions@^2.2.1:
- version "2.2.1"
- resolved "https://registry.yarnpkg.com/firebase-functions/-/firebase-functions-2.2.1.tgz#f5b6de47860819eb8d41b969c8d6d2c1000dc422"
- integrity sha512-k2FA3j8XFGPOGBjgKoBUQQc4Hfqe4PdcG8hfS/RHireW1vQhkplx8XhzaknJNqsBCIoglMFuUsXpuAh9pbhtxw==
+firebase-functions@^2.3.0:
+ version "2.3.0"
+ resolved "https://registry.yarnpkg.com/firebase-functions/-/firebase-functions-2.3.0.tgz#89433939b05f3cf2b8b617409b7b51963fd2a5d3"
+ integrity sha512-bUhaX5aW5SaLxDsC+F7Phbbb4KPPYyn4XlhqR8jdQCbiQMC9udxIOYy21d+vGR2XvSPH2fE7vgHsvOOzEQ0SmQ==
  dependencies:
  "@types/cors" "^2.8.1"
  "@types/express" "^4.11.1"