Update AUTHORS and acknowledgements again

Author: sophiebits

AUTHORS

@@ -98,6 +98,7 @@ Josh Bassett <josh.bassett@gmail.com>
 Josh Duck <josh@fb.com>
 Josh Yudaken <yud@instagram.com>
 Joshua Ma <me@joshma.com>
+Julen Ruiz Aizpuru <julenx@gmail.com>
 Jun Wu <quark@lihdd.net>
 Juraj Dudak <jdudak@fb.com>
 Justin Jaffray <justinjaffray@khanacademy.org>

docs/acknowledgements.md

@@ -110,6 +110,7 @@ We'd like to thank all of our contributors:
     <li>Josh Duck</li>
     <li>Josh Yudaken</li>
     <li>Joshua Ma</li>
+    <li>Julen Ruiz Aizpuru</li>
     <li>Jun Wu</li>
     <li>Juraj Dudak</li>
     <li>Justin Jaffray</li>