Fix AppVeyor x64 Windows pre-compiled binary generation
Fix AppVeyor x64 Windows pre-compiled binary generation

Tell AppVeyor to explicitly use the Node.js binary matching the
current architecture. This has a good chance of fixing
https://github.com/addaleax/lzma-native/issues/13.

addaleax/lzma-native,addaleax/lzma-native,addaleax/lzma-native,addaleax/lzma-native