Add badges for tests
See https://docs.gitlab.com/ee/user/project/pipelines/settings.html#badges for how to use GitLab for badges. Using e.g. shields.io is fine as well, if that turns out to be easier.
See https://docs.gitlab.com/ee/user/project/pipelines/settings.html#badges for how to use GitLab for badges. Using e.g. shields.io is fine as well, if that turns out to be easier.