Implement the ability to create and publish a revoke document

The revoke document should be implemented before identity #90.

Add revoke command with following options:

-i, --immediately
-s, --save-document
-p, --publish-document
-v, --verify-document #to check the doc consistency and the associated identity
--dry-run

It would be great to allow the user to choose a custom path for saving, publication and verify.