Add Raphael to AUTHORS.

AUTHORS

@@ -36,7 +36,7 @@ Alexander Dorokhine, Corentin Chary, Wouter Van Meir, George Kiagiadakis,
 Joel Martin, Gernot Tenchio, William Roberts, Cristian Rodríguez,
 George Fleury, Kan-Ru Chen, Steve Guo, Luca Stauble, Peter Watkins,
 Kyle J. McKay, Mateus Cesar Groess, Philip Van Hoof, D. R. Commander,
-Rostislav Lisovy and Oliver Loch.
+Rostislav Lisovy, Oliver Loch and Raphael Kubo da Costa.
 
 Probably I forgot quite a few people sending a patch here and there, which
 really made a difference. Without those, some obscure bugs still would