Copyright for mutagen source package in Focal

Format: https://www.debian.org/doc/packaging-manuals/copyright-format/1.0/
Upstream-Name: Mutagen
Upstream-Contact: Christoph Reiter 
Source: https://bitbucket.org/lazka/mutagen

Files: *
Copyright: 2005-2006, 2009 Joe Wreschnig 
           2005 Michael Urman
           2006-2007 Lucas Lalinsky 
           2012-2014 Christoph Reiter 
           2014 Ben Ockmore
           2014 Evan Purheiser
License: GPL-2

Files: debian/*
Copyright: 2005-2006 Joe Wreschnig 
           2006-2014 Tristan Seligmann 
License: GPL-2

License: GPL-2
 This program is free software; you can redistribute it and/or modify
 it under the terms of the GNU General Public License version 2 as
 published by the Free Software Foundation.
 .
 On Debian systems, the GNU GPL version 2 can be found in
 /usr/share/common-licenses/GPL-2.

Files: mutagen/ac3.py
Copyright: Copyright (C) 2019 Philipp Wolfer
License: GPL-2

Files: mutagen/tak.py
Copyright: Copyright (C) 2008  Lukáš Lalinský
 Copyright (C) 2019  Philipp Wolfer
License: GPL-2