Propagate errors in tls_config instead of unwrap/panic

[repi]

Motivation

We ran into tls_connector failing and causing our app to panic and shutdown as it seems there wasn't any way to avoid panicking in tls_config.

Solution

So after talking to @LucioFranco briefly tls_config now returns a Result instead and propagates errors to the caller, where they have to be handled.

This is a bit of an intrusive change to the API here. could alternatively introduce an additional tls_config function that does the error handling and keep the existing unwrapping one, to allow it to become an additive opt-in minor semver change instead?

[LucioFranco]

This seems 👍 to me @jen20 thoughts?

[LucioFranco]

@repi looks like a CI failure https://github.com/hyperium/tonic/pull/385/checks?check_run_id=831660623#step:7:139

[LucioFranco]

Thanks!

[jen20]

Sorry, I didn't see this until now - this looks great to me.

[fujiapple852]

Note that Cargo's modified SemVer logic treats 0.2.2 as a compatible update from 0.2.1 and thus this release of tonic causes a break. Trivial to fix but perhaps yanking and releasing as 0.3.0 would be better?

[LucioFranco]

@fujiapple852 you're right.....sigh will do that today.

[LucioFranco]

Getting a 0.3.0 release out right now. @fujiapple852 thanks for pointing this out!