Add an appveyor.yml file

Author: kevinkuszyk

appveyor.yml

@@ -0,0 +1,16 @@
+version: '{build}'
+image: Visual Studio 2019
+configuration: Release
+
+before_build:
+- cmd: dotnet restore
+
+artifacts:
+  - path: '**\*.nupkg'
+  
+deploy:
+- provider: NuGet
+  api_key:
+    secure: x6Qtht6EqnrMnwvUCCiTcewdgCsKXM63vHDcmtvZ8KweHN4iIVtexIuKBSfZf9QF
+  on:
+    appveyor_repo_tag: true