This is needed badly. I am a huge Golang advocate, but I refuse to use the "github.com" package naming/folder setup mess. It's just not elegant.
We even do it with just an S3 bucket for go.mozilla.org: https://go.mozilla.org/
The S3 method is kinda experimental. It works for first-level packages but fails for nested packages. We need to look into setting up redirects for those.
The best way to do this yourself is to run an instance of https://github.com/niemeyer/gopkg, but that's not #serverless anymore ;)