Fix 'gnt-group add' output in QA
Fix 'gnt-group add' output in QA

The command 'gnt-group add' might return a list of jobs, therefore, we
can print the job's output during the QA, in a way similar to that of
'gnt-cluster verify', for example.

Signed-off-by: Jose A. Lopes <0fb9c4f8511df4ec2ae28af879e9d462f6218a2c@google.com>
Reviewed-by: Hrvoje Ribicic <be5828fca31f89218048bec4189e30a581aa65da@google.com>

ganeti/ganeti,yiannist/ganeti,mbakke/ganeti,dimara/ganeti,mbakke/ganeti,bitemyapp/ganeti,andir/ganeti,apyrgio/ganeti,apyrgio/ganeti,yiannist/ganeti,ganeti/ganeti,andir/ganeti,leshchevds/ganeti,onponomarev/ganeti,leshchevds/ganeti,ganeti-github-testing/ganeti-test-1,andir/ganeti,grnet/snf-ganeti,leshchevds/ganeti,yiannist/ganeti,bitemyapp/ganeti,mbakke/ganeti,grnet/snf-ganeti,ganeti-github-testing/ganeti-test-1,onponomarev/ganeti,ganeti/ganeti,dimara/ganeti