Add option to exclude roles from get_urls

[WoosterInitiative]

Intead of explicitly choosing which roles to include, get all except for those that have been excluded with exclude.

CRUDView.get_urls(exclude=[Role.LIST])

Will raise exception if both roles and exclude are provided. exclude is a named parameter.

[carltongibson]

FWIW a comprehension will give you want you're looking for without the need for the extra option...

roles=[r for r in Role if r != Role.LIST]