Update AUTHORS/CONTRIBUTORS (#471)

As requested, in a pr form :)
diff --git a/AUTHORS b/AUTHORS
index a25ad72..cb1080d 100644
--- a/AUTHORS
+++ b/AUTHORS
@@ -34,6 +34,7 @@
 Oleksandr Sochka <sasha.sochka@gmail.com>
 Paul Redmond <paul.redmond@gmail.com>
 Radoslav Yovchev <radoslav.tm@gmail.com>
+Roman Lebedev <lebedev.ri@gmail.com>
 Shuo Chen <chenshuo@chenshuo.com>
 Yixuan Qiu <yixuanq@gmail.com>
 Yusuke Suzuki <utatane.tea@gmail.com>
diff --git a/CONTRIBUTORS b/CONTRIBUTORS
index 952b99b..457e0ea 100644
--- a/CONTRIBUTORS
+++ b/CONTRIBUTORS
@@ -52,6 +52,7 @@
 Radoslav Yovchev <radoslav.tm@gmail.com>
 Raul Marin <rmrodriguez@cartodb.com>
 Ray Glover <ray.glover@uk.ibm.com>
+Roman Lebedev <lebedev.ri@gmail.com>
 Shuo Chen <chenshuo@chenshuo.com>
 Tobias Ulvgård <tobias.ulvgard@dirac.se>
 Tom Madams <tom.ej.madams@gmail.com> <tmadams@google.com>