Rewrite bin/gitlab-shell-authorized-keys-check and bin/gitlab-shell-authorized-principals-check in Go
These are two simple wrappers around the GitLab API to generate
authorized_keys lines in the face of two different configurations:
- "Fast SSH key lookup" - sshd is configured with
- Certificate-based SSH authentication - sshd is configured with
They both need to be rewritten if we're to remove all Ruby code from the gitlab-shell project. Since they're invoked per-SSH-session in both of these configurations, additionally to the
bin/gitlab-shell script, there are some latency wins from doing so.