Look forward to an image that includes 1.58+

[EdmundsEcho]

Thank you for this image. It's my goto for rust builds.

How could this project be improved?
Only as an FYI, rust 1.58 allows for a more friendly build of url strings not supported in 1.57. Specifically, the following is a "nice to have":

let host = &CONFIG.options.tnc_auth_host;
let prefix = &CONFIG.options.tnc_auth_prefix;
let endpoint = &CONFIG.options.tnc_authorized_endpoint;
let auth_service = &CONFIG.options.auth_service;

// easier to track how the uri is being constructed...
let redirect_uri = format!("{host}/{prefix}{endpoint}/{auth_service}");

If you're interested in implementing this feature yourself, how could I help you?
... I did look at the Dockerfile. It was not clear to me where exactly I needed to at least try with a newer version. It might of course not be so easy depending on the dependencies :)) Let me know though.

[hoijui]

Related to PR #134