The Sandbox constructor was getting out of control, and this allows
binding regtest options directly to the sandbox configuration struct.
Change-Id: I18da4ddf43c86b3b652516c3ddca7726cd35e3b2
Reviewed-on: https://go-review.googlesource.com/c/tools/+/244439
Run-TryBot: Robert Findley <rfindley@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Heschi Kreinick <heschi@google.com>