Add operator controllers tests for deployment rollouts
Summary
Part of https://gitlab.com/charts/gitlab/issues/945
Our operator controller tests are currently only test that reconcile runs. https://gitlab.com/charts/components/gitlab-operator/blob/master/pkg/controller/gitlab/gitlab_controller_test.go
We need to further flush out these tests to cover the behavioural logic we have inside the controller.
The functions that need test coverage for checking the rollouts are:
- rollingUpdateGitaly
- finishGitlabDeployment
- rollingUpdateGitLab
- checkStatefulSetFinished
- checkDeploymentFinished