Update EKS version to 1.17

[geerlingguy]

See: aws/containers-roadmap#697

[geerlingguy]

(And here's the issue for 1.18: aws/containers-roadmap#809)

[abdennour]

Also this link might be useful terraform-aws-modules/terraform-aws-eks#949
I know that here it is about ansible roles... but let's see which one will be the first available: TF module or Ansible role.