Add support for API servers on IPv6 addresses (#48)

* Remove duplicate file for deletion

* Add support for IPv6 clusters

To correctly escape IPv6 addresses when ports are used, they must be
wrapped in square brackets [1]. This patch adds support for that,
using Ansible's ipwrap filter [2].

[1]: https://datatracker.ietf.org/doc/html/rfc4038#section-5.1
[2]: http://docs.ansible.com/ansible/latest/collections/ansible/utils/docsite/filters_ipaddr.html#wrapping-ipv6-addresses-in-brackets

* Do not abort other molecule jobs on failure

* Fix cache keys for Vagrant boxes

* Molecule: Derive overrides.yml location from scenario dir

# Conflicts:
#	molecule/default/molecule.yml
#	molecule/ipv6/molecule.yml

roles/k3s/post/templates/metallb.crs.j2

@@ -5,7 +5,14 @@ metadata:
   namespace: metallb-system
 spec:
   addresses:
-  - {{ metal_lb_ip_range }}
+{% if metal_lb_ip_range is string %}
+{# metal_lb_ip_range was used in the legacy way: single string instead of a list #}
+{#   => transform to list with single element #}
+{% set metal_lb_ip_range = [metal_lb_ip_range] %}
+{% endif %}
+{% for range in metal_lb_ip_range %}
+  - {{ range }}
+{% endfor %}
 ---
 apiVersion: metallb.io/v1beta1
 kind: L2Advertisement