This commit adds a new `golden_test.go` file into the helm chart
which essentially renders the chart with a set of values and
compares that with the expected golden file, and errors if
they don't match.
This builds on the existing CI values files in `ci/` directory. As
this is the first time, The golden files are rendered and added. This
means for all the future changes, The golden files can be updated
by running `go test -update` and the CI will fail if the golden files
are not updated. By doing this, Both the committer and reviewer
can be sure that the changes are intentional, without having to render
the chart manually.
