Does not handle groups using "no access" pseudo role

[andersonshatch]

Testing revealed that groups using the no access role will cause a crash...
The endpoint to list groups does not return role information if the "no access" option is used, but it is returned when getting details about one group by ID.
If a group is encountered where the role cannot be determined, we could either assume it should be "no access", or possibly grab the response for that specific group to mirror it to the destination instance.