Merge branch 'debian-license' into 'master'

Fixed incorrect statement of license in debian packaging

See merge request !18

debian/copyright

@@ -3,9 +3,9 @@ Source: https://git.ligo.org/lscsoft/ligo-segments
 
 Files: *
 Copyright: 2011, LIGO Scientific Collaboration
-License: GPL-2+
+License: GPL-3
 
-License: GPL-2+
+License: GPL-3
  This program is free software; you can redistribute it
  and/or modify it under the terms of the GNU General Public
  License as published by the Free Software Foundation; either