Helpers & other dependencies managed by the DIC

Delegating the management of the logger, the ssh helper and the default set of task helpers,

Adding a new default helper is as easy as adding a new key at the KorikoContainer. For future extensions, the container is also customizable/extensible.

This KorikoContainer is just a Pimple container with the default components as a logger, a ssh driver or the MySQL helper. If the isolation between task helpers and the other components is a requirement, the helpers could be encapsulated inside another container embeded in the main one.

The cost of this improvement is the 'init' call before running the app (see the diff at tests or the bin/koriko file)

The 'pimple' branch is merged with your 'introducting_actions'.