Add support for AccountKeyRollover. API only returns an error since acme.Error will contain appropriate KID lookup information. Due to the requirements of double JWS encoding jwsEncodeJSON is also modified to support a missing Nonce header and raw string embedding in the payload. Fixes golang/go#42516 Change-Id: I959660a1a39b2c469b959accd48fda519daf4eb3 GitHub-Last-Rev: 8e8cc5b094743262939c145f56d3a3b57a057d64 GitHub-Pull-Request: golang/crypto#215 Reviewed-on: https://go-review.googlesource.com/c/crypto/+/400274 TryBot-Result: Gopher Robot <gobot@golang.org> Reviewed-by: Heschi Kreinick <heschi@google.com> Reviewed-by: Roland Shoemaker <roland@golang.org> Run-TryBot: Roland Shoemaker <roland@golang.org>