ocsp: add Request.Marshal method

Tests that Marshaling a parsed response
returns the same bytes as were parsed.

Use Marshal in CreateRequest;
still passes CreateRequest's golden test.

Change-Id: I427ef8372d7b62c43b7718d7d90631d022377d32
Reviewed-on: https://go-review.googlesource.com/19488
Run-TryBot: Russ Cox <rsc@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>
2 files changed