Hammer CLI

Cloned from https://bugzilla.redhat.com/show_bug.cgi?id=1253737
Description of problem:
Hammer currently does not return valid json, when requested, if the output is a simple message like "____ deleted" or "Activation key copied".

Version-Release number of selected component (if applicable):
Satellite 6.1 GA

How reproducible:
Always

Steps to Reproduce:
1. Run a command that only returns a message stating that it passed, specifying --output=json
2. View results

Actual results:
hammer --output=json activation-key copy --name=tester --new-name=copykey --organization-id=3
Activation key copied

Expected results:
hammer --output=json activation-key copy --name=tester --new-name=copykey --organization-id=3 {'Message':'Activation key copied'}