* ci: redefine multinode to node-etcd-client

This should allow to catch several class of problem rather than just
one -> from network plugin such as calico or cilium talking directly to
the etcd.

* Dynamically define etcd host range

This has two benefits:
- We don't play the etcd role twice for no reason
- We have access to the whole cluster (if needed) to use things like
  group_by.

* Add multinode ci layout

* Add test case for calico using etcd datastore

* Rename aio to all-in-one and document it

ADTM.
Acronyms don't tell much.

* Refactor vm_count in tests provisioning

This replaces master with "control plane" in Kubespray docs
because of [1].

[1]: https://github.com/kubernetes/enhancements/blob/master/keps/sig-cluster-lifecycle/kubeadm/2067-rename-master-label-taint/README.md#motivation

* rename ansible groups to use _ instead of -

k8s-cluster -> k8s_cluster
k8s-node -> k8s_node
calico-rr -> calico_rr
no-floating -> no_floating

Note: kube-node,k8s-cluster groups in upgrade CI
      need clean-up after v2.16 is tagged

* ensure old groups are mapped to the new ones

This replaces kube-master with kube_control_plane because of [1]:

  The Kubernetes project is moving away from wording that is
  considered offensive. A new working group WG Naming was created
  to track this work, and the word "master" was declared as offensive.
  A proposal was formalized for replacing the word "master" with
  "control plane". This means it should be removed from source code,
  documentation, and user-facing configuration from Kubernetes and
  its sub-projects.

NOTE: The reason why this changes it to kube_control_plane not
      kube-control-plane is for valid group names on ansible.

[1]: https://github.com/kubernetes/enhancements/blob/master/keps/sig-cluster-lifecycle/kubeadm/2067-rename-master-label-taint/README.md#motivation

Broken since 4efb0b78

New deploy modes: scale, ha-scale, separate-scale
Creates 200 fake hosts for deployment with fake hostvars.

Useful for testing certificate generation and propagation to other
master nodes.

Updated test cases descriptions.

Signed-off-by: Bogdan Dobrelya <bdobrelia@mirantis.com>

Signed-off-by: Bogdan Dobrelya <bdobrelia@mirantis.com>

Run 1 of each part1/2/special for Gitlab CI only for PRs
Remaining 2/3 of each stage are manual steps for master only (merges)

Signed-off-by: Bogdan Dobrelya <bdobrelia@mirantis.com>

* Reduce default testcase to 2 nodes, add HA case.
* Adjust gen_matrix script for Travis/Gitlab CIs.
* Enable netchecker deploy foro gitlab CI.
* Sync other things from travis matrix and reorder them as build steps
  for pull requests, master branch, auto/manual.
* Do auto-step1 from part1 and manual step2,3 for branches/PRs.
* Do manual steps from part2, special for master merges.

Signed-off-by: Bogdan Dobrelya <bdobrelia@mirantis.com>

Signed-off-by: Bogdan Dobrelya <bdobrelia@mirantis.com>

Reduce the test cases from 15 to 9, bearing in mind that:
* Disable weave/coreos gate unless its deployment fixed
* If debian/centos7 fails with net plugin X, ubuntu-xenial/rhel-7 will
  likely fail as well
* Canal also covers the flannel plugin deployment, but keep at least one
  of the flannel plugin deployment, unless it's superseded and removed.
* Keep at least one of each OS/plugin family to be tested in the separate
  nodes layout
* Keep at least one of each OS family to be tested against each of the
  plugin types in default nodes layout
* Rebalance GCE regions for instances, replace asia to eu/us as they
  are the longest running jobs.

Signed-off-by: Bogdan Dobrelya <bdobrelia@mirantis.com>

Signed-off-by: Bogdan Dobrelya <bdobrelia@mirantis.com>

For Travis CI and GCE, add a naive generator script into a markdown table.
Add GCE/Travis CI matrix docs.
Add CoreOS test cases.
Rework existing cases w/o loosing of coverage.
Rework postinstall tests to support CoreOS as well.

Signed-off-by: Bogdan Dobrelya <bdobrelia@mirantis.com>