Update LICENSE.txt

Author: XORxes-1

LICENSE.txt

@@ -3,11 +3,11 @@ The MIT License (MIT)
 Copyright 2019 Arash J. Farmand
 
 Permission is hereby granted, free of charge, to any person obtaining a copy of
-this software and associated documentation files (Quadtree.java, AABB.java), to 
-deal in the Software without restriction, including without limitation the
-rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
-copies of the Software, and to permit persons to whom the Software is furnished
-to do so, subject to the following conditions:
+this software and associated documentation files (Quadtree.java, AABB.java and
+Tester.java), to deal in the Software without restriction, including without
+limitation the rights to use, copy, modify, merge, publish, distribute,
+sublicense, and/or sell copies of the Software, and to permit persons to whom
+the Software is furnished to do so, subject to the following conditions:
 
 The above copyright notice and this permission notice shall be included in all
 copies or substantial portions of the Software.