Two bugtrackers

[michal-josef-spacek]

We have two bug trackers actually. I think that's not fine.
https://rt.cpan.org/Public/Dist/Display.html?Name=GnuPG-Interface
https://github.com/bestpractical/gnupg-interface/issues

I am proposing:

1. Add bug tracker to Makefile.PL (GitHub) → Add bugtracker #9
2. Move RT issues to GitHub. (one of the convertors - https://github.com/briandfoy/perlrt2github)

[michal-josef-spacek]

The root cause for this activity was https://src.fedoraproject.org/rpms/perl-GnuPG-Interface/pull-request/1