[pango] [test] Include header

[Behdad Esfahbod <behdad src gnome org>]

commit 762afd93b3be04ae475de3cfd433a2a1b70dac1a
Author: Behdad Esfahbod <behdad behdad org>
Date:   Mon May 4 23:46:15 2015 -0700

    [test] Include header

 tests/test-common.c |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)
---
diff --git a/tests/test-common.c b/tests/test-common.c
index 8823411..17b5df3 100644
--- a/tests/test-common.c
+++ b/tests/test-common.c
@@ -25,6 +25,7 @@
 #include <locale.h>
 
 #include <pango/pangocairo.h>
+#include "test-common.h"
 
 char *
 diff_with_file (const char  *file,