Without this, autocert will panic with an unhelpful nil pointer inside the acme client. Reorganized the test suite's ACME server stub creation, as I needed to be able to stand up a test where GetCertificate was expected to fail. Change-Id: Ie5e19c6e7766b4578c9b3c16789d7b27bd3be163 Reviewed-on: https://go-review.googlesource.com/40951 Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org> Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org> TryBot-Result: Gobot Gobot <gobot@golang.org>