Make it possible to use static analysis for HAML templates
See https://gitlab.com/gitlab-org/gitlab-ce/issues/19944
It may be a good idea to use tool like https://github.com/brigade/haml-lint to use static analysis for HAML templates.
Unfortunately haml-lint
depends on haml
gem, which we replaced with hamlit
, so I'm not sure if we can use it easily.