Adjust behavior of roles table on organizations page #113
Description
Currently, the default roles are only visible if there's at least one custom role. We want them to always be visible. Also, the default roles are editable. We actually need to prevent them from being edited, especially since these roles only exist once in the database for all orgs, not once for each org. We should create tests to verify the desired behavior, and then we should change the roles modal. I think it will be a relatively straightforward set of changes.