v3.0.5 with initial support for Cygwin

Changes since v3.0.5

• lib/apt-cyg: Add initial support for apt-cyg on Cygwin systems
• Rewrote bin/gen_tests.rb in bash (@mondeja)
• Minor typo/tests fixes

WARNING

The script won't work with docker container image opensuse/tumbleweed:latest. See also
https://bugzilla.opensuse.org/show_bug.cgi?id=1190670
and moby/moby#42836

Notes

Some tests are failing, but it's due to upstream and/or tests problems.