Define proper network policies

[hcadavid]

• V6 algorithm for testing the network policies

Fine-tune Job PODs network policies so that:

• The job PODs are able to resolve the NODE-PROXY FQDN (consider e.g., not blocking the DNS port)
• The job pods can't reach any other external host

[hcadavid]

@frankcorneliusmartin and @CunliangGeng the changes to address this are now on the PoC: PRs #46 and #45, and #44

Something to consider: the new network policies defined for the Job PODs running the algorithms have one difference with the ones implemented on the docker-manager: they have an 'exception' rule that allows these PODs to use kubernetes' DNS service, as they need it to resolve the Node's FQDN.