Add missing includes
diff --git a/include/git2.h b/include/git2.h
index f260cfa..2e33f9e 100644
--- a/include/git2.h
+++ b/include/git2.h
@@ -38,6 +38,8 @@
#include "git2/config.h"
#include "git2/remote.h"
+#include "git2/attr.h"
+#include "git2/branch.h"
#include "git2/refspec.h"
#include "git2/net.h"
#include "git2/status.h"