CONTRIBUTORS: add Alexandru Moșoi <brtzsnr@gmail.com>

Google contributor.

R=golang-dev, iant
CC=golang-dev
https://golang.org/cl/5554084

CONTRIBUTORS

@@ -39,6 +39,7 @@ Aleksandar Dezelin <dezelin@gmail.com>
 Alex Brainman <alex.brainman@gmail.com>
 Alexander Orlov <alexander.orlov@loxal.net>
 Alexander Reece <awreece@gmail.com>
+Alexandru Moșoi <brtzsnr@gmail.com>
 Alexey Borzenkov <snaury@gmail.com>
 Amrut Joshi <amrut.joshi@gmail.com>
 Andrea Spadaccini <spadaccio@google.com>