[glom] Add missing iostream include.

[Murray Cumming <murrayc src gnome org>]

commit 9e7214c9b3565743dad93131878902838db40cc2
Author: Murray Cumming <murrayc murrayc com>
Date:   Mon Oct 26 14:13:08 2015 +0100

    Add missing iostream include.
    
    Something else must have included this until now.

 tests/python/test_python_module.cc |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)
---
diff --git a/tests/python/test_python_module.cc b/tests/python/test_python_module.cc
index fe0ab88..2195624 100644
--- a/tests/python/test_python_module.cc
+++ b/tests/python/test_python_module.cc
@@ -1,6 +1,7 @@
 #include <Python.h>
 #include <cstdio>
 #include <libglom/init.h>
+#include <iostream>
 
 #include "config.h"
 #include "glom/python_embed/glom_python.h"