Small fixes in the main script, few additionall unittests
Small fixes in the main script, few additionall unittests

Change-Id: I60591b6ec958762c8d1d358a782280cc89bab0c7
Reviewed-on: https://gerrit.spotify.net/gerrit/73017
Reviewed-by: Paweł Rozlach <bb6340f668e0a0e9a9592e4f835bf23c6026f908@spotify.com>

spotify/certcheck