Add v6 unit test for service_auth_tokens_command
Add v6 unit test for service_auth_tokens_command

[#164098152]

Signed-off-by: Brendan Smith <8591d66a77fc00d117843ef4d4bc1fbb80fd377f@pivotal.io>

cloudfoundry/cli,cloudfoundry/cli,cloudfoundry/cli