Implement sml as go type parameters

cmd/hepto/config.go

go.mod

go.sum

pkg/cluster/cluster.go

pkg/cluster/config.go

pkg/cluster/meta.go

pkg/cluster/pki.go

pkg/pki/cert.go

pkg/pki/pki.go

pkg/selfcontain/container.go

pkg/sml/delegate.go

pkg/sml/memberlist.go

pkg/sml/node.go

test.go