Also update reset.yml to do more dns/network related cleanup.

Do not run unit-tests for master merges.
Fix the permissive "null" user.

Signed-off-by: Bogdan Dobrelya <bogdando@mail.ru>

For security and resources utilization reasons, do not auto-start CI
for opened/updated PRs.

A member of the kubernetes-incubator github org has first to approve
that the PR is reasonable to test by putting the "ci check this" into
the PR's comments.

If approved that way, the CI pipeline starts as always. Only the 1st step
of the pipeline is premoderatied, the rest will follow each over on
success.

Signed-off-by: Bogdan Dobrelya <bogdando@mail.ru>

* Run CI triggers in one step
* Run all test matrix for triggers
* Switch back to g1-small

Signed-off-by: Bogdan Dobrelya <bogdando@mail.ru>

Includes tox support for running unit tests.
Small note added to getting-started guide for using
inventory_builder.py

Also adds manual-only unit test.

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

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>