Visual Studio 2015 image causes AppVeyor build to time out, reverting to 2017 image but with v141_xp toolset (#793).
Visual Studio 2015 image causes AppVeyor build to time out, reverting to 2017 image but with v141_xp toolset (#793).

csound/csound,ketchupok/csound,csound/csound,csound/csound,ketchupok/csound,csound/csound,ketchupok/csound,ketchupok/csound,csound/csound,csound/csound,csound/csound,csound/csound,ketchupok/csound,csound/csound,ketchupok/csound,ketchupok/csound,ketchupok/csound,ketchupok/csound,ketchupok/csound,csound/csound