What does this MR do?
This is Backport of CE implementation as suggested by the ee compatibility check. https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/10649
Adds deployment history to the metrics graphs. The AJAX request happens after the metrics AJAX request so that we know the SVG is rendered before attempting to add anything else into it.
I did notice some discrepancies against the design to what we currently have, tried to address some of that here but I think most of is best for another merge request.
What are the relevant issue numbers?