I added tests for all the commands which work reliably in container mode.
Some tests are naive, some are more sophisticated. While going
through the tests, I think I found a small bug in `osctl gen keypair`.
When we get reliable KVM tests, I can revisit and add missing
tests for time, reboot, shutdown and friends.
Signed-off-by: Andrey Smirnov <smirnov.andrey@gmail.com>
