firebase-auth-2-signinwithgithub.dart

void signInWithGitHub() async {
    const String url = "https://github.com/login/oauth/authorize?client_id=" + CLIENT_ID
       + "&scope=user:email";

    if (await canLaunch(url)) {
      await launch(url);
    } else {
      throw "Could not launch $url";
    }
  }