getUserProfile method
Makes an API call to google to get the users profile.
Implementation
Future<GoogleUser> getUserProfile() async {
var request = new Request(HttpMethod.Get,
"https://www.googleapis.com/oauth2/v1/userinfo?alt=json");
var resp = await send(request);
var json = Convert.jsonDecode(resp.body);
return GoogleUser.fromJson(json);
}