The package golang-github-letsencrypt-challtestsrv 1.2.0+ds-2 has been added to kali-rolling. It has been imported from Debian: https://tracker.debian.org/pkg/golang-github-letsencrypt-challtestsrv -- More information about golang-github-letsencrypt-challtestsrv: http://pkg.kali.org/pkg/golang-github-letsencrypt-challtestsrv