Also:
* declared scanner resources as an enum type
* replaced stdlib json, added uit tests for skipped resources
* unexported worker pool
* more unexported methods (i.e. everything that is not part of the interface)
* refact(core): clarified mock injection logic and added a few unit tests at the caller's (CLI init utils)
Signed-off-by: Frederic BIDON <fredbi@yahoo.com>
