code: @DELETE
      @Path("{group}/{id}")
      public SuccessResponse deleteRole(@PathParam("group") String group, @PathParam("id") String id,
                                        final @Authenticated Subject subject) {
          _uac.deleteRole(subject, new EmoRoleKey(group, id));
          return SuccessResponse.instance();
      }
docs: RESTful endpoint for deleting a role.