Update to 7.40, add a new TEST_DEPENDS on Role::Tiny, and pet portlint.
- Added support for Role::Tiny extensions to all classes based on Mojo::Base. (dotan)
- Added with_roles method to Mojo::Base. (dotan)
- Added the guide Mojolicious::Guides::Testing. (scottw)
- Replaced systemd detection in Mojo::Log with the MOJO_LOG_SHORT environment variable, since there is no reliable way to detect systemd.