Added a new method cloneable? to check if VMs/Templates can be cloned or not

issue #253
https://bugzilla.redhat.com/show_bug.cgi?id=1122712
I think you might be testing the wrong thing here. All you're doing is testing the ```#cloneable?``` method that we already have tested in the other spec files you created. I think what we want is to make sure that ```subject``` returns true unless the VmOrTemplate is cloneable.