k8s: Drop support for Casablanca

k8s: Drop support for Casablanca

Casablanca release reached End of Life (EOL) stage on July 8th 2019 [1].

This patch also fixes comments for test fixtures.

This whole test subtree will be deleted upon migrating Aquasec
kube-bench [2] for CIS Benchmark [3] integrated by Orange [4] to ONAP
xtesting [5].

[1] https://wiki.onap.org/display/DW/Long+Term+Roadmap
[2] https://github.com/aquasecurity/kube-bench
[3] https://www.cisecurity.org/benchmark/kubernetes/
[4] https://gitlab.com/Orange-OpenSource/lfn/onap/integration/xtesting
[5] https://git.onap.org/integration/xtesting/

Issue-ID: SECCOM-235
Change-Id: Ifc7d9c775c27d4cfafdd1932809288530cffceff
Signed-off-by: Pawel Wieczorek <p.wieczorek2@samsung.com>