If one input and one output to PropsSI, bubble error cleanly; closes #375
If one input and one output to PropsSI, bubble error cleanly; closes #375

CoolProp/CoolProp,dcprojects/CoolProp,CoolProp/CoolProp,CoolProp/CoolProp,DANA-Laboratory/CoolProp,CoolProp/CoolProp,henningjp/CoolProp,JonWel/CoolProp,CoolProp/CoolProp,DANA-Laboratory/CoolProp,henningjp/CoolProp,JonWel/CoolProp,henningjp/CoolProp,DANA-Laboratory/CoolProp,JonWel/CoolProp,henningjp/CoolProp,CoolProp/CoolProp,CoolProp/CoolProp,DANA-Laboratory/CoolProp,dcprojects/CoolProp,dcprojects/CoolProp,dcprojects/CoolProp,henningjp/CoolProp,JonWel/CoolProp,DANA-Laboratory/CoolProp,henningjp/CoolProp,dcprojects/CoolProp,CoolProp/CoolProp,DANA-Laboratory/CoolProp,dcprojects/CoolProp,henningjp/CoolProp,JonWel/CoolProp,JonWel/CoolProp,henningjp/CoolProp,JonWel/CoolProp,dcprojects/CoolProp,DANA-Laboratory/CoolProp