treewide: comply with the OpenBMC style guidelines

The guidelines say cpp source code filenames should be lower_snake_case:
https://github.com/openbmc/docs/blob/master/cpp-style-and-conventions.md#files

Signed-off-by: Brad Bishop <bradleyb@fuzziesquirrel.com>
Change-Id: Ia04017b0eb9a65ce1303af5b6dc36e730410fd91
diff --git a/test/test_entity-manager.cpp b/test/test_entity-manager.cpp
index b1eec84..4cd841a 100644
--- a/test/test_entity-manager.cpp
+++ b/test/test_entity-manager.cpp
@@ -1,4 +1,4 @@
-#include "Utils.hpp"
+#include "utils.hpp"
 
 #include <nlohmann/json.hpp>
 
diff --git a/test/test_fru-utils.cpp b/test/test_fru-utils.cpp
index 60b71e0..5a6ce52 100644
--- a/test/test_fru-utils.cpp
+++ b/test/test_fru-utils.cpp
@@ -1,4 +1,4 @@
-#include "FruUtils.hpp"
+#include "fru_utils.hpp"
 
 #include <algorithm>
 #include <array>