bmc/ver.../test/.close_unittest: add missing header

Signed-off-by: Patrick Venture <venture@google.com>
Change-Id: I836986ee7108caa651a374c3f08e96029d01cd9c
diff --git a/bmc/version-handler/test/version_close_unittest.cpp b/bmc/version-handler/test/version_close_unittest.cpp
index 941f72d..5717cca 100644
--- a/bmc/version-handler/test/version_close_unittest.cpp
+++ b/bmc/version-handler/test/version_close_unittest.cpp
@@ -3,6 +3,7 @@
 
 #include <memory>
 #include <string>
+#include <unordered_map>
 #include <vector>
 
 #include <gtest/gtest.h>