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

.github/workflows/test.yml

@@ -15,6 +15,7 @@ jobs:
       matrix:
         scenario:
           - default
+          - ipv6
           - single_node
       fail-fast: false
     env:
@@ -25,16 +26,19 @@ jobs:
         uses: actions/checkout@2541b1294d2704b0964813337f33b291d3f8596b # 3.0.2
 
       - name: Configure VirtualBox
-        run: >-
-          sudo mkdir -p /etc/vbox &&
-          echo "* 192.168.30.0/24" | sudo tee -a /etc/vbox/networks.conf > /dev/null
+        run: |-
+          sudo mkdir -p /etc/vbox
+          cat <<EOF | sudo tee -a /etc/vbox/networks.conf > /dev/null
+          * 192.168.30.0/24
+          * fdad:bad:ba55::/64
+          EOF
 
       - name: Cache Vagrant boxes
         uses: actions/cache@fd5de65bc895cf536527842281bea11763fefd77 # 3.0.8
         with:
           path: |
             ~/.vagrant.d/boxes
-          key: vagrant-boxes-${{ hashFiles('**/Vagrantfile') }}
+          key: vagrant-boxes-${{ hashFiles('**/molecule.yml') }}
           restore-keys: |
             vagrant-boxes