C: add Hana Kim (Google CLA)

LGTM=crawshaw
R=golang-codereviews, crawshaw
CC=golang-codereviews, iant
https://golang.org/cl/150690043

CONTRIBUTORS

@@ -256,6 +256,7 @@ Gustav Paul <gustav.paul@gmail.com>
 Gustavo Franco <gustavorfranco@gmail.com>
 Gustavo Niemeyer <gustavo@niemeyer.net> <n13m3y3r@gmail.com>
 Gwenael Treguier <gwenn.kahz@gmail.com>
+Hana Kim <hyangah@gmail.com>
 Han-Wen Nienhuys <hanwen@google.com>
 Harley Laue <losinggeneration@gmail.com>
 Hector Chu <hectorchu@gmail.com>