Update header in Makefile

Makefile

 ############################################################################
 #
-# Copyright (c) 2015 PX4 Development Team. All rights reserved.
+# Copyright (c) 2015 - 2016 PX4 Development Team. All rights reserved.
 #
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions