Update appveyor.yml

This is really needed for troubleshooting.

appveyor.yml

@@ -62,6 +62,7 @@ build_script:
 #- ps: $blockRdp = $true; iex ((new-object net.webclient).DownloadString('https://raw.githubusercontent.com/appveyor/ci/master/scripts/enable-rdp.ps1'))
 
 artifacts:
+- path: update_info.xml
 - path: gist.md
 
 notifications: