lazily create warg registry client

[calvinrp]

Due to the change in the warg-client to support the .well-known config redirection, creating the client triggers lookups. So we need to adjust the code to lazily instantiate the registry client to avoid unnecessarily triggering usage.

Fixes #122

[thomastaylor312]

Thanks for the quick fix! Should this also bump the patch version to 0.2.1 so it can be released as a fix?

[calvinrp]

Thanks for the quick fix! Should this also bump the patch version to 0.2.1 so it can be released as a fix?

Technically, it changes a pub method to &mut self from &self. It might be better as 0.3.0. Is that OK, @thomastaylor312 ?

[thomastaylor312]

Oh yep you're right. Definitely a 0.3 in that case IMO, but really up to you