Clang-Tidy fixes

Change-Id: I58900a452591315a39754b329e94b315c34926cd
diff --git a/internal/ceres/block_jacobian_writer.cc b/internal/ceres/block_jacobian_writer.cc
index 4f1834a..544e913 100644
--- a/internal/ceres/block_jacobian_writer.cc
+++ b/internal/ceres/block_jacobian_writer.cc
@@ -32,6 +32,7 @@
 
 #include <algorithm>
 #include <memory>
+#include <vector>
 
 #include "ceres/block_evaluate_preparer.h"
 #include "ceres/block_sparse_matrix.h"