Add myself to the AUTHORS (#4254)

CONTRIBUTORS.txt

@@ -249,3 +249,4 @@ Sammie S. Taunton, 2017/08/17
 Kxrr, 2017/08/18
 Mads Jensen, 2017/08/20
 Markus Kaiserswerth, 2017/08/30
+Andrew Wong, 2017/09/07