Add tests for all scripts

[mickeyn]

• setup (eq. of t/0* in api)
• author.pl
• backpan.pl
• backup.pl
• check.pl
• checksum.pl
• contributor.pl
• cover.pl
• cpan_testers_api.pl
• cpan_testers.pl
• cve.pl
• external.pl
• favorite.pl
• first.pl
• latest.pl
• mapping.pl
• mirrors.pl
• package.pl
• permission.pl
• purge.pl
• queue.pl
• release.pl
• restart.pl
• river.pl
• session.pl
• snapshot.pl
• suggest.pl
• tickets.pl
• watcher.pl