We are now starting to formally deprecate Appveyor in favor of Azure for
builds on the win platform. Note that we have not been adding appveyor
to new feedstocks for a while, so this is not a completely new change in
policy. We will now, however, begin to actively disable Appveyor builds
on feedstocks not using it by turning off builds for GitHub push
events. Additionally, we have been issuing PRs to any remaining
feedstocks to move them to Azure. We are aware that some packages built
with msbuild cannot yet be moved to Azure and so are leaving Appveyor
on for those feedstocks for now.