Copyright for r-cran-htmltools source package in Oracular

Format: https://www.debian.org/doc/packaging-manuals/copyright-format/1.0/
Upstream-Contact: Joe Cheng 
Upstream-Name: htmltools
Source: https://cran.r-project.org/package=htmltools

Files: *
Copyright: 2013-2017 Joe Cheng 
License: GPL-2+

Files: debian/*
Copyright: 2016-2017 Andreas Tille 
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 as published by
    the Free Software Foundation; either version 2 of the License, or
    (at your option) any later version.
 .
    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.
 .
    You should have received a copy of the GNU General Public License
    along with this program; if not, write to the Free Software
    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 .
 On Debian systems, the complete text of the GNU General Public
 License can be found in `/usr/share/common-licenses/GPL-2'.