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

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

Pre download all required container images as roles' deps.
Drop unused flannel-server-helper images pre download.
Improve pods creation post-install test pre downloaded busybox.
Improve logs collection script with kubectl describe, fix sudo/etcd/weave
commands.

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

The test deployment/rc/pods creation time
is near 2m on slow CI instances with 1 CPU/1.7G RAM.
Increase wait time to allow the post test fail less often.

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>