Add basic .appveyor.yml file.

.appveyor.yml

diff --git a/.appveyor.yml b/.appveyor.yml
new file mode 100644
index 0000000..0ba8bbc
--- /dev/null
+++ b/.appveyor.yml
@@ -0,0 +1,21 @@
+version: 1.0.{build}

+environment:

+  ZLIB_VERSION: 1.2.11

+install:

+- ps: >-

+    appveyor DownloadFile "https://github.com/madler/zlib/archive/v$env:ZLIB_VERSION.zip" -FileName zlib.zip

+

+    7z x zlib.zip -oC:\

+

+    Rename-Item -path "c:\zlib-$env:ZLIB_VERSION" -newName "c:\zlib"

+before_build:

+- cmd: >-

+    cd vstudio

+

+    RMDIR /S /Q zlib

+

+    robocopy C:\zlib zlib /S /NP || EXIT /B 0

+

+    .\vsbuild.cmd build+test "Visual Studio 12 Win64" v120

+build:

+  verbosity: minimal
\ No newline at end of file