Ability to reduce verbosity

If you don't want to see the output of all the skipped host, you can set
this value to 'False'.
This will dramatically reduce the output of the run.

Closes: #32

Signed-off-by: Sébastien Han <sebastien.han@enovance.com>
Merge pull request #33 from leseb/feature-reduce-verbose

Ability to reduce verbosity