Add Appveyor for Windows CI

Author: xzyfer

appveyor.yml

@@ -0,0 +1,56 @@
+-
+  os: Visual Studio 2013
+
+  configuration: release
+
+  platform:
+    - x64
+    - x86
+
+  version: "{build}"
+
+  cache:
+    - '%userprofile%\.node-gyp'
+    - '%AppData%\npm-cache'
+
+  environment:
+    matrix:
+      - nodejs_version: 0.10
+        GYP_MSVS_VERSION: 2013
+        APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2013
+      - nodejs_version: 0.12
+        GYP_MSVS_VERSION: 2013
+        APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2013
+      - nodejs_version: 1
+        GYP_MSVS_VERSION: 2013
+        APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2013
+      - nodejs_version: 2
+        GYP_MSVS_VERSION: 2013
+        APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2013
+      - nodejs_version: 3
+        GYP_MSVS_VERSION: 2013
+        APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2013
+      - nodejs_version: 4
+        GYP_MSVS_VERSION: 2013
+        APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2013
+      - nodejs_version: 5
+        GYP_MSVS_VERSION: 2013
+        APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2013
+      - nodejs_version: 6
+        GYP_MSVS_VERSION: 2015
+        APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2015
+      - nodejs_version: 7
+        GYP_MSVS_VERSION: 2015
+        APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2015
+      - nodejs_version: 8
+        GYP_MSVS_VERSION: 2015
+        APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2015
+      - nodejs_version: 9
+        GYP_MSVS_VERSION: 2015
+        APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2015
+
+  install:
+    - ps: Install-Product node $env:nodejs_version $env:platform
+    - node --version
+    - npm --version
+    - npm install