add appveyor.yml

appveyor.yml

@@ -0,0 +1,17 @@
+environment:
+  matrix:
+  - TARGET: nightly-x86_64-pc-windows-msvc
+  - TARGET: nightly-i686-pc-windows-msvc
+  - TARGET: nightly-x86_64-pc-windows-gnu
+  - TARGET: nightly-i686-pc-windows-gnu
+install:
+  - ps: Start-FileDownload "https://static.rust-lang.org/dist/rust-${env:TARGET}.exe" -FileName "rust-install.exe"
+  - ps: .\rust-install.exe /VERYSILENT /NORESTART /DIR="C:\rust" | Out-Null
+  - ps: $env:PATH="$env:PATH;C:\rust\bin"
+  - rustc -vV
+  - cargo -vV
+build_script:
+  - cargo build
+test_script:
+  - cargo test
+  - cargo bench