Add `version` command

[vdye]

Closes #17

This pull request contains a smattering of CI/CD updates as well as the addition of the git-bundle-server version command.

CI/CD changes

• The first two commits here update the main.yml workflow to run Makefile targets rather than custom go (build|vet|test) invocations.
• The third commit updates release.yml to match only the exact set of patterns we want for releases (the previous pattern would allow tags like v1a.2b.3c-d.4ef).

git-bundle-server version

• The fourth commit introduces the git-bundle-server version command, which prints a (currently unset) globally-accessible version string compiled into the program.
• The fifth commit updates the Makefile to determine the VERSION if it is not set by a user, then compiles that value into git-bundle-server using -ldflags.

CC: @jeffhostetler (since this is based on your recommendation in an earlier PR)

[vdye]

Overall, looks really good! The one thing I'm having trouble with is getting the new command to work locally (although I recognize this is probabaly just me holding it wrong). Here's what I'm seeing:

make output

ldennington@Lessleys-MBP:~/repos/git-bundle-server(vdye/version-cmd○) » make
rm -f -r /Users/ldennington/repos/git-bundle-server/bin
GOOS="darwin" GOARCH="amd64" go build -o /Users/ldennington/repos/git-bundle-server/bin -ldflags "-X 'github.com/github/git-bundle-server/cmd/utils.Version='" ./...

git-bundle-server version output

ldennington@Lessleys-MBP:~/repos/git-bundle-server(vdye/version-cmd○) » ./bin/git-bundle-server version
git-bundle-server version <no version>

git tag --list output

ldennington@Lessleys-MBP:~/repos/git-bundle-server(vdye/version-cmd○) » git tag --list
v0.0.1
v0.1.0
v0.1.1
v0.1.2
v0.2.0

@ldennington the issue is that none of those tags are on the main branch, so they're not in the ancestry path searched by git describe, so no version is found. If you locally tag the main branch with v<something>, does that work?

[ldennington]

@ldennington the issue is that none of those tags are on the main branch, so they're not in the ancestry path searched by git describe, so no version is found. If you locally tag the main branch with v<something>, does that work?

That worked! Thanks for clarifying.