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  of the flannel plugin deployment, unless it's superseded and removed.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>