[SD-1003] Role cannot inherit itself as its ancestor

I would like to have built a more complex test for the inheritance, something like create Role A, create Role B that extends Role A Then try to make Role A extend role B, Amy ideas how to do this? 
The inner "if" detects the special case of a role extending its self, the outer "if" is strictly not required but it will stop the call to the check_parents function when the patch does not include an extends avoiding a call to fine_one, I think this is good!