Add support for kerberos ticket management

[SvenvDam]

Hi there,

Thanks for the work you put into this repo! I'm currently working on implementing this at my company and was thinking of adding support for automatic ticket generation and refreshing to TSaslClientTransport using https://github.com/krbcontext/python-krbcontext.

Would you be open to a contribution if I manage to implement this?
Let me know!

[normal-cock]

Thanks for you invitation. I'm sorry that I don't have enough time to do that.