Execute test suite using minitest 4.x.
add spacing to changelog
Update to Asciidoctor 0.1.5.preview.6

- Use HTTPS URLs
- Support Minitest 5
- Adjustments for https://fedoraproject.org/wiki/Changes/Ruby_2.1
- Mark CHANGELOG, LICENSE, READMEs as %doc
- Remove Rakefile in %prep
- Remove Requires: /usr/bin/env