I was running into an issue where i wanted more information from the
TwoFactorChallengeFailedException. It turns out, the exception could
easily provide both the TwoFactorType AND the authentication code
provided. So 💥!
It's bothered me that our response models are mutable. They really
shouldn't be. I made the properties have a protected setter instead of
private to provide flexibility for others who might be deriving from
these classes or testing them.
Fixes#650
Right now, our exception messages come from the API response in most
cases. But if for any reason there isn't one, we supply a default. I
realized these messages might make it to people's logs so it might be
nice to spend time later making them even more useful.
