build: add codereview.cfg
build: add codereview.cfg

See golang.org/cl/4131 for context.

Change-Id: If794246b854f3a26727c0f99633ef295e20f2034
Reviewed-on: https://go-review.googlesource.com/7762
Reviewed-by: David Crawshaw <a2f0bf29257797dd66800b4fbb9945c3e216c004@golang.org>

proppy/build,evandbrown/build,proppy/build,golang/build,golang/build,evandbrown/build,golang/build,evandbrown/build,proppy/build,golang/build,proppy/build