appveyor integration is busted

[jdm]

Build started
git clone -q https://github.com/servo/libexpat.git C:\projects\libexpat
git fetch -q origin +refs/pull/22/merge:
git checkout -qf FETCH_HEAD
The build phase is set to "MSBuild" mode (default), but no Visual Studio project or solution files were found in the root directory. If you are not building Visual Studio project switch build mode to "Script" and provide your custom build command.