On top of that, "fast, automatic TLS HTTP2 capable web server" is not some complex feat in Go. HTTP2 is already baked into the stdlib, and you can add automatic TLS via LE in a few lines of code: https://godoc.org/golang.org/x/crypto/acme/autocert.
A few alternatives:
https://github.com/labstack/armor
https://github.com/containous/traefik