Add security checks

Add security checks

This patch adds initial security validation check. It includes JSON file
containing dictionary of acknowledged NodePorts with corresponding
services [1].

Data required to perform added security check cannot be easily obtained
from within "robot" pod (without granting it access to "kubectl" tool
and as a side effect - cluster modifications). That is why it should be
collected beforehand by the test operator and stored as a JSON file.

Added suite expects having "${ACTUAL_NODEPORTS_FILE}" variable defined.
It will attempt parsing data stored in the file pointed by the said
variable and compare it against expected NodePorts.

[1] https://docs.onap.org/en/elalto/guides/onap-developer/settingup/index.html#nodeports

Issue-ID: SECCOM-261
Change-Id: Ib8078c50e943125f8452120368891c3e3a7056bc
Signed-off-by: Pawel Wieczorek <p.wieczorek2@samsung.com>