This PR adds Goreleaser to eventually replace the custom release build in build.sh

build.sh currently fails on building the Freno .deb package due to errors in fpm. I sunk a lot of time into this and couldn't resolve it:

Doing `require 'backports'` is deprecated and will not load any backport in the next major release.
Require just the needed backports instead, or 'backports/latest'.
epoch in Version is set {:epoch=>"1", :level=>:warn}
Process failed: tar failed (exit code 1). Full command was:["tar", "-C", "/var/folders/3w/1p_7mtc14fx73q7j1sgg5tg00000gn/T/package-deb-build-de4b31e44e3786a37490be5c8cb8c28d2ff6ad32219c6da902697a026532/control", "-z", "-cf", "/var/folders/3w/1p_7mtc14fx73q7j1sgg5tg00000gn/T/package-deb-build-de4b31e44e3786a37490be5c8cb8c28d2ff6ad32219c6da902697a026532/control.tar.gz", "--owner=0", "--group=0", "--numeric-owner", "."] {:level=>:error}

I'd prefer to move to Goreleaser because:

1. It builds all assets successfully using many architectures
2. It's a well maintained project / not custom code
3. It doesn't rely on a special gem / Ruby setup (just Golang)
4. It works seamlessly in GitHub Actions
5. It generates a changelog and checksums automatically
6. No more manual steps to build a release

To test this I merged this PR to my timvaillancourt/freno fork and created a 1.0.5 release via GitHub, which triggered the "goreleaser" GitHub action that resulted in this auto-generated release (changelog, packages/asset uploads, checksums): https://github.com/timvaillancourt/freno/releases/tag/v1.0.5 🎉

Once this is stable we can start to deprecate the custom bash/ruby-based build