Solve cmake build error: include\catch.hpp(1938): error C2678: binary '<<': no operator found  which takes a left-hand operand of type 'std::ostringstream' (#1535)
Solve cmake build error: include\catch.hpp(1938): error C2678: binary '<<': no operator found  which takes a left-hand operand of type 'std::ostringstream' (#1535)

* Change variable passing method

* Change & to .str()

henningjp/CoolProp,CoolProp/CoolProp,CoolProp/CoolProp,CoolProp/CoolProp,CoolProp/CoolProp,henningjp/CoolProp,henningjp/CoolProp,henningjp/CoolProp,CoolProp/CoolProp,henningjp/CoolProp,henningjp/CoolProp,CoolProp/CoolProp,henningjp/CoolProp,henningjp/CoolProp,CoolProp/CoolProp,CoolProp/CoolProp