Steve Newman (Google CLA) was missing from the CONTRIBUTORS file,
presumably because his old commits (made prior to Go being open
source) in SVN/perforce were imported into hg/git later as
"devnull@localhost", which probably didn't match anything, and we
didn't start tracking CLA contributions prior to the Go
open source release.

As a fun historical note, the initial HTTP client from Steve:
https://github.com/golang/go/commit/f315fb3

Change-Id: I2b8da4564d99820504788ecc41495a62391078d5
Reviewed-on: https://go-review.googlesource.com/16864Reviewed-by: Ian Lance Taylor <iant@golang.org>