Replace use of deprecated C Standard library headers in C++ code.

Change-Id: I9fa6630c7e4bdb2897df34d417635d8c7d8253bc
Signed-off-by: Tyler Chatow <tchatow@gmail.com>
diff --git a/y2019/jevois/spi.h b/y2019/jevois/spi.h
index 8b16d5c..59e321a 100644
--- a/y2019/jevois/spi.h
+++ b/y2019/jevois/spi.h
@@ -1,12 +1,11 @@
 #ifndef Y2019_JEVOIS_SPI_H_
 #define Y2019_JEVOIS_SPI_H_
 
-#include <stdint.h>
-
 #include <array>
+#include <cstdint>
+#include <optional>
 
 #include "third_party/GSL/include/gsl/gsl"
-#include <optional>
 #include "y2019/jevois/structures.h"
 
 // This file manages serializing and deserializing the various structures for