cleanup Section constructor
enable CI reports

- code coverage (locally & for shippable.com builds) (use `rake coverage test:all`)
- JUnit-style XML reports (for shippable.com builds)
upgrade thread_safe gem to 0.3.4
Merge pull request #1190 from mojavelinux/shippable-ci-reports

enable CI reports
Preserves URI with protocol in PathResolver.web_path

Resolves #1192