C: add John Newlin (Google CLA)

R=golang-codereviews, iant
CC=golang-codereviews
https://golang.org/cl/45830043

CONTRIBUTORS

@@ -270,6 +270,7 @@ John Beisley <huin@google.com>
 John DeNero <denero@google.com>
 John Graham-Cumming <jgc@jgc.org> <jgrahamc@gmail.com>
 John Howard Palevich <jack.palevich@gmail.com>
+John Newlin <jnewlin@google.com>
 John Shahid <jvshahid@gmail.com>
 Jonathan Allie <jonallie@google.com>
 Jonathan Feinberg <feinberg@google.com>