Copyright for php-pubsubhubbub-publisher source package in Focal

Format: https://www.debian.org/doc/packaging-manuals/copyright-format/1.0/
Upstream-Name: php-pubsubhubbub-publisher
Upstream-Contact: Josh Fraser 
Source: https://github.com/pubsubhubbub/php-publisher

Files: *
Copyright: 2015-2018 Josh Fraser 
License: Apache-2.0

Files: debian/*
Copyright: 2020 James Valleroy 
License: Apache-2.0

License: Apache-2.0
 On Debian systems the full text of the Apache-2.0 license can be found in
 /usr/share/common-licenses/Apache-2.0.