test(windows): add appveyor ci

.appveyor.yml

@@ -0,0 +1,23 @@
+environment:
+    CARGO_TARGET: x86_64-pc-windows-gnu
+    matrix:
+        - TARGET: x86_64-pc-windows-msvc
+        - TARGET: i686-pc-windows-gnu
+install:
+    - ps: Start-FileDownload "https://static.rust-lang.org/dist/rustc-nightly-${env:TARGET}.tar.gz"
+    - ps: Start-FileDownload "https://static.rust-lang.org/cargo-dist/cargo-nightly-${env:CARGO_TARGET}.tar.gz"
+    - 7z x rustc-nightly-%TARGET%.tar.gz > nul
+    - 7z x rustc-nightly-%TARGET%.tar > nul
+    - 7z x cargo-nightly-%CARGO_TARGET%.tar.gz > nul
+    - 7z x cargo-nightly-%CARGO_TARGET%.tar > nul
+    - call "C:\Program Files (x86)\Microsoft Visual Studio 12.0\VC\vcvarsall.bat" amd64
+    - set PATH=%PATH%;%cd%/rustc-nightly-%TARGET%/rustc/bin
+    - set PATH=%PATH%;%cd%/cargo-nightly-%CARGO_TARGET%/cargo/bin
+    - SET PATH=%PATH%;C:\MinGW\bin
+    - rustc -V
+    - cargo -V
+
+build: false
+
+test_script:
+    - cargo test --verbose --no-default-features