Add Appveyor configuration

Author: codebling

appveyor.yml

@@ -0,0 +1,9 @@
+environment:
+  nodejs_version: "8"
+
+# Install scripts. (runs after repo cloning)
+install:
+  # Get the latest stable version of Node.js or io.js
+  - ps: Install-Product node $env:nodejs_version
+  # install modules
+  - npm install