snappy: C: add Marc-Antoine Ruel (Google CLA).

R=dsymonds
CC=golang-dev, maruel
https://codereview.appspot.com/7312082

CONTRIBUTORS

@@ -27,6 +27,7 @@
 # Please keep the list sorted.
 
 Kai Backman <kaib@golang.org>
+Marc-Antoine Ruel <maruel@chromium.org>
 Nigel Tao <nigeltao@golang.org>
 Rob Pike <r@golang.org>
 Russ Cox <rsc@golang.org>