Add /version endpoint and --version cli flag

[jgknight]

Summary

Closes #18

Allow the server operator a way to view the current RAS version with either the CLI or API.

The CLI allows for -v, --v, -version or --version. There's also -h output

GoReleaser by default sets the main.version, main.commit, and main.date variables.

Testing

Help output

./retro_aim_server -h       
Usage of ./retro_aim_server:
  -v    Display build information
  -version
        Display build information

On a non-release build, it will show a dev version with no commit or date information.

./retro_aim_server --version
version:   dev
commit:    none
date:      unknown

curl -s localhost:8080/version | jq
{
  "version": "dev",
  "commit": "none",
  "date": "unknown"
}

I made a release build by running make release-dry-run. The latest tag I had checked out was 0.8.0 so that's the version it built with, but in a normal situation this should show the latest tag. The output shows the version, latest commit, and the date it was built.

./retro_aim_server -v
version:   0.8.0
commit:    2e0cf4181ab3cb4df6ebc4f84d7c16a591aacb8d
date:      2024-08-29T20:28:00Z

curl -s localhost:8080/version | jq
{
  "version": "0.8.0",
  "commit": "2e0cf4181ab3cb4df6ebc4f84d7c16a591aacb8d",
  "date": "2024-08-29T20:28:00Z"
}

Also added unit tests for the /version endpoint which pass

[mk6i]

very nice 🌮