Abstract crane components

[aexvir]

Right now all the workflow depends on the GitLab -> Rancher deployment itself. If we would abstract the different components and we make them available directly from the CI we could use the crane integrations without having to do the deployment with crane itself, like in the case of Kubernetes.

GitLab integrates nicely with Kubernetes and can deploy directly to clusters, so having the different integrations easily callable from the image could allow us keep the same notifications to slack and integrations with datadog while using the GitLab integration for deployments.

We could also integrate the autodevops logic into crane, but that is something else that needs to be maintained and kept in sync. Moreover, having those components abstracted and easily callable can help also with developing different deployment workflows.