Update library version to 1.15.0

Author: bessudnov

src/AmoCRM/Client/AmoCRMApiRequest.php

@@ -36,7 +36,7 @@ class AmoCRMApiRequest
     public const CONNECT_TIMEOUT = 5;
     public const REQUEST_TIMEOUT = 20;
     //TODO Do not forget to change this on each release
-    public const LIBRARY_VERSION = '1.9.1';
+    public const LIBRARY_VERSION = '1.15.0';
     public const USER_AGENT = 'amoCRM-API-Library/' . self::LIBRARY_VERSION;
 
     public const SUCCESS_STATUSES = [