* Replace `openstack_compute_secgroup_v2` with `openstack_networking_secgroup_v2`

The `openstack_networking_secgroup_v2` resource allow specifications of
both ingress and egress. Nova security groups define ingress rules only.

This change will also allow for more user-friendly specified security
rules, as the different security group resources have different HCL
syntax.

allow masters, nodes and gluster nodes (within each group) to be scheduled
on differents AZ.

* Add supplementary node groups

  To add additional ansible groups to the k8s nodes, such as
  `kube-ingress` for running ingress controller pods. Empty by default.

* [terraform/openstack] Restores ability to use existing public nodes and masters as bastion.

* [terraform/openstack] Uses network_id as output

* [terraform/openstack] Fixes link to inventory/local/group_vars

* [terraform/openstack] Adds supplementary master groups

* [terraform/openstack] Updates documentation avoiding manual setups for bastion (as they are not needed now).

* [terraform/openstack] Supplementary master groups in docs.

* [terraform/openstack] Fixes repeated usage of master fips instead of bastion fips

* [terraform/openstack] Missing change for network_id to subnet_id

* [terraform/openstack] Changes conditional to element( concat ) form to avoid type issues with empty lists.

* Adding bastion and private network provisioning for openstack terraform

* Remove usage of floating-ip property

* Combine openstack instances + floating ips

* Fix relating floating IPs to hosts for openstack builds

* Tighten up security groups

Allow ssh into all instances with floating IP

* Add the gluster hosts to the no-floating group

* Break terraform into modules

* Update README and var descriptions to match current config

* Remove volume property in gluster compute def

* Include cluster name in internal network and router names

* Make dns_nameservers a variable