Added AppVeyor config.

Author: WilliamABradley

appveyor.yml

@@ -0,0 +1,23 @@
+image: Visual Studio 2017
+
+branches:
+  only:
+  - master
+
+skip_branch_with_pr: true
+nuget:
+  disable_publish_on_pr: true
+  
+skip_commits:
+  files:
+    - 'docs/**/*.*'  
+    - 'README.md'
+    
+init:
+- ps: git config --global core.autocrlf true
+
+build_script:
+- ps: .\build\build.ps1
+
+artifacts:
+- path: .\build\nupkg\*.nupkg