iam roles (#116)

internal/db/migrations/postgres/04_iam.down.sql

@@ -6,6 +6,8 @@ drop table iam_scope_project cascade;
 drop table iam_scope_organization cascade;
 drop table iam_scope cascade;
 drop table iam_scope_type_enm cascade;
+drop table iam_role cascade;
+
 
 drop function iam_sub_names cascade;
 drop function iam_immutable_scope_type_func cascade;