tests CHANGE add tests for including submodules

based on #1353
diff --git a/tests/utests/schema/test_schema.c b/tests/utests/schema/test_schema.c
index 7e7a351..dd9e34c 100644
--- a/tests/utests/schema/test_schema.c
+++ b/tests/utests/schema/test_schema.c
@@ -40,6 +40,7 @@
 void test_revisions(void **state);
 void test_typedef(void **state);
 void test_accessible_tree(void **state);
+void test_includes(void **state);
 
 /* test_schema_stmts.c */
 void test_identity(void **state);
@@ -55,6 +56,7 @@
         UTEST(test_revisions),
         UTEST(test_typedef),
         UTEST(test_accessible_tree),
+        UTEST(test_includes),
 
         /** test_schema_stmts.c */
         UTEST(test_identity),