Update appveyor deployment settings

Author: natemcmaster

.appveyor.yml

@@ -5,19 +5,24 @@ clone_depth: 1
 branches:
   only:
     - master
-    - release
     - dev
-    - /^(.*\/)?ci-.*$/
+    - appveyor
 build_script:
   - ps: .\build.ps1
 environment:
   global:
     DOTNET_SKIP_FIRST_TIME_EXPERIENCE: true
     DOTNET_CLI_TELEMETRY_OPTOUT: 1
 test: off
-deploy: off
 os: Visual Studio 2017
 artifacts:
   - path: artifacts/*.nupkg
     name: Packages
     type: NuGetPackages
+deploy:
+  - provider: NuGet
+    skip_symbols: true
+    api_key:
+      secure: MIhcKhOCOJ64Cdf6S+uBuvKS0mSHsDSLxuXCAASqPDL/Wcgo8TAJMIR3p2Y4OqvP
+    on:
+      appveyor_repo_tag: true