removed old test

include/boost/math/differentiation/test_fwdiff_behavior.cpp

@@ -1,17 +0,0 @@
-#include "autodiff.hpp"
-#include<iostream>
-
-using namespace boost::math::differentiation;
-
-double myabs(double x)
-{
-	return (x>0) - (x<0);
-}
-int main()
-{
-	float y = -0.26647448539733887;
-	float z = 0.8725948333740234;
-	float w = abs(y);
-	std::cout<<w<<std::endl;
-	return 0;
-}