qtlint linter for qt

Hi everyone,

I use `quicktest` on almost all of my projects. What I lacked in all of them is linting. As there were no other alternatives, I created a `quicktest`-specific linter that detects suboptimal or non-idiomatic assertion patterns and can automatically apply fixes: https://github.com/go-extras/qtlint

The linter is intentionally focused on quicktest semantics rather than generic test linting, and the rule set is designed to be minimal and extensible.

Contributions, ideas for additional rules, and feedback are welcome.