Auto-update dependencies. (#303)

https://firebase.google.com/support/release-notes/admin/node#version_720_-_march_28_2019

Author: dpebot

functions/functions/package.json

@@ -10,7 +10,7 @@
     "logs": "firebase functions:log"
   },
   "dependencies": {
-    "firebase-admin": "~7.1.1",
+    "firebase-admin": "~7.2.0",
     "firebase-functions": "^2.2.1",
     "bad-words": "^1.3.1",
     "capitalize-sentence": "^0.1.2"