Clean up build / runtime warnings

[igbanam]

When I tried building and running the tools, I realized there were some warnings output with the runtime / build-time text. Thankfully, these errors made sense™ to me despite my rust-fu being technically non-existent at the moment. So I thought to do something about it.

There were two classes of warnings:

1. Unused imports
2. Unreachable code

I'm pretty confident about the "unused imports" warnings; since this is something my editor can help with. The "unreachable code" bits, I had to trust that the tests already existing in the package would fail if I broke something.

Changelog:

• Implement orb config and orb serve subcommands (#92)
• Remove unused imports
• Change todo! to // TODO: so Ok(()) is reachable.

p.s: I'm not responsible for the first point here, but it's part of my changeset. If Github doesn't filter this out, I'll work on cleaning it up.

[cdata]

Ahh, sorry, one more thing: we require signed commits. Would you be willing to sign your commits and update this change?

Instructions for setting this up on Github: https://docs.github.com/en/authentication/managing-commit-signature-verification/signing-commits

[igbanam]

When you said PRs expected signed commits, I thought the most recent should be a signed commit. Just realized all commits should be signed. I've hopefully fixed that now