C: add Burcu Dogan (Google CLA)

LGTM=bradfitz
R=golang-codereviews, bradfitz
CC=golang-codereviews
https://golang.org/cl/94610043

CONTRIBUTORS

@@ -116,6 +116,7 @@ Brian G. Merrell <bgmerrell@gmail.com>
 Brian Gitonga Marete <marete@toshnix.com>
 Brian Ketelsen <bketelsen@gmail.com>
 Brian Slesinsky <skybrian@google.com>
+Burcu Dogan <jbd@google.com>
 Caine Tighe <arctanofyourface@gmail.com>
 Caleb Spare <cespare@gmail.com>
 Carl Chatfield <carlchatfield@gmail.com>