Fixed OAuthAppAuthorization not throwing TransportException

`OAuthAppAuthorization` does not handle non-200 responses on auth, instead a wrong (or in my case, rejected because of rate limiting) login intent causes nothing to happen until a subsequent intent to call the API results in an `AttributeError` caused by the missing `token`.
I changed it to work like `OAuthAuthorization` -- the exception is thrown inside `_handle_response`.