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/y2021_bot3/constants.h b/y2021_bot3/constants.h
index fa95550..02c08bc 100644
--- a/y2021_bot3/constants.h
+++ b/y2021_bot3/constants.h
@@ -1,10 +1,9 @@
 #ifndef Y2021_BOT3_CONSTANTS_H_
 #define Y2021_BOT3_CONSTANTS_H_
 
-#include <math.h>
-#include <stdint.h>
-
 #include <array>
+#include <cmath>
+#include <cstdint>
 
 #include "frc971/constants.h"
 #include "frc971/control_loops/pose.h"