- move required fields before optional in the Client struct - prefix all errors with "acme: " - rename tos to tosURL (Terms of Service) Change-Id: I6914b7e75d1e0559ff8303d390238c2a27145c8e Reviewed-on: https://go-review.googlesource.com/27010 Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>