Gets Firebase auth tokens (for development purposes only)

1. Create Firebase project
2. Setup Firebase authentication
3. Setup Google IDP
4. Create "Web" application for Firebase
5. Navigate to Web application credentials in GoogleCloud: API & Services > Credentials > Web Client
6. Add localhost to "Authorized redirect URIs" e.g. http://localhost:5000/__/auth/handler
7. Download JSON
8. Ensure Firebase service account exists in Firebase: Project Settings > Service Accounts > Create Service Account (if doesn't already exist)
9. Copy Firebase Admin APIKey in GoogleCloud: API & Services > Credentials > API Keys > the one which says (auto created by Firebase)
10. Get tokens go run main.go --apiKey xyz123 --config ~/Downloads/yourfirebasewebappconfig.json

go install github.com/mousybusiness/firebase_token then simply firebase_token --help

go run main.go --apiKey xyz123 --config ~/Downloads/yourfirebasewebappconfig.json --refresh YOUR_REFRESH_TOKEN

go run main.go --apiKey xyz123 --config ~/Downloads/yourfirebasewebappconfig.json --refresh YOUR_REFRESH_TOKEN --token

LOG_LEVEL=debug go run main.go ...