Run cargo check on Appveyor

[pietroalbini]

This PR adds a basic Windows CI to Crater, to avoid we regress in platform support. cargo build is not run because SQLite is missing from image and I have near zero experience developing on Windows.

Fixes #275

[Eh2406]

I looked into getting SQLite on appveyor:
appveyor recommends using vcpkg
but the problematic dep it self
rusqlite uses ps: Start-FileDownload
but then its docs describe having vcpkg integration or adding the "bundled" feature to have it built from source.

So it may be just doing the setup from appveyor for vcpkg.

[pietroalbini]

I don't have too much Windows experience, if you can get a PR for this up I'll happily merge it :)