Hammer should end with error when unknown output adapter is selected
Hammer defaults to 'base' output adapter if it can't find adapter specified in --output:
hammer --output=unknown user list Id: 3 Login: admin Name: Admin User Email: email@example.com Admin: yes Last login: 2017/10/20 11:21:39 Authorized by: Internal Id: 52 Login: ipa_bob Name: Bob Doe Email: firstname.lastname@example.org Admin: no Last login: 2017/07/13 12:36:02 Authorized by: FreeIPA ldap
This is quite confusing behavior, especially when user passes 'yml' instead of the only supported 'yaml'. Both outputs aren't that different at a first glance.
Hammer should end with error instead, informing that the adapter name is unknown and listing the available ones.