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/y2018/control_loops/python/arm_bounds.cc b/y2018/control_loops/python/arm_bounds.cc
index 2c7b94c..1515192 100644
--- a/y2018/control_loops/python/arm_bounds.cc
+++ b/y2018/control_loops/python/arm_bounds.cc
@@ -3,7 +3,8 @@
 #include <CGAL/Exact_predicates_inexact_constructions_kernel.h>
 #include <CGAL/Polygon_2_algorithms.h>
 #include <CGAL/squared_distance_2.h>
-#include <math.h>
+
+#include <cmath>
 #include <iostream>
 
 namespace y2018 {