bugfix: fix typo dry_run_on_unkown -> dry_run_on_unknown

careful: API-change! (we are still in pre-release 1.x.x so this is ok).
Signed-off-by: Dominik Richter <dominik.richter@gmail.com>
typo fix

Signed-off-by: Dominik Richter <dominik.richter@gmail.com>
Merge pull request #18 from TelekomLabs/typo_fix_dry_run

Typo fix dry run