Foreman Maintain

Add --whitelist option

Allows to mark some steps to be ignored in the results: allows to
continue even when some checks are failing.

Full upgrade scenario

This commit intoroduces more structured upgrade scenario consisting of
this scenarios:

• pre_upgrade_check - non-modifying checks: is the system ready?
• pre_migrations - modifying procedures before source update
• migrations - source update and main migrations...

Assumeyes option

Improve reporting on hammer setup and preparation steps

Hammer setup preparation step

Support running commands interactively

RFE #23 - Add new status [WARNING] - Check: is system self registered

Decouple more reporter from runner

Before this commit, we required the reporter to call back runner
methods, which complicated the things. Also the multiple-steps select
was not working properly.

After this change, the reporter just returns a decision as result of...

Check count of paused tasks and offer next steps

Fixes #3 - Add option to skip the prompted step

Done changes for rubocop v0.48.1

Make the spinner opt-in, not opt-out

The default spinner caused issues when one needs to interact with the
user (printing additional messages). As it's needed only for long
running actions, it should not be enforced by default.

Refactor the choice of next steps

Tests for runner and reporter