Stop deleting the templated client on logout

[ada-globus]

[sirosen]

Does the login path not need any adjustment?

That was something I've been meaning to check, but since there's an approval on this, I want to comment before it merges.

That's my only point of concern; very happy with the new tests and so forth.

[sirosen]

I just read down the path I was worried about -- login with no tokens in the presence of the templated client -- and it's all good. The entire codepath follows a "get-or-create" paradigm. That was my only hesitation, so I think we're good to go!