Update LICENSE

Author: jmadler

LICENSE

@@ -1,6 +1,6 @@
-The MIT License (MIT)
+Modified MIT License
 
-Copyright (c) 2016 Bastian Bartmann
+Copyright 2021 OneSignal
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal
@@ -9,9 +9,12 @@ 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
+1. The above copyright notice and this permission notice shall be included in
 all copies or substantial portions of the Software.
 
+2. All copies of substantial portions of the Software may only be used in connection
+with services provided by OneSignal.
+
 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE