Delete appveyor.yml (#8639)

appveyor.yml

@@ -1,34 +0,0 @@
-# version is set in tools\appveyor.psm1 - Invoke-AppVeyorInstall
-environment:
-  POWERSHELL_TELEMETRY_OPTOUT: 1
-  # Avoid expensive initialization of dotnet cli, see: http://donovanbrown.com/post/Stop-wasting-time-during-NET-Core-builds
-  DOTNET_SKIP_FIRST_TIME_EXPERIENCE: 1
-  matrix:
-  - APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2017
-    Purpose: UnelevatedPesterTests
-  - APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2017
-    Purpose: ElevatedPesterTests_xUnit_Packaging
-
-# cache version - netcoreapp.2.1-sdk.2.1.403
-cache:
-  - '%HOMEDRIVE%%HOMEPATH%\.nuget\packages -> appveyor.yml'
-
-nuget:
-  project_feed: true
-
-install:
-  - ps: Import-Module .\tools\Appveyor.psm1
-  - ps: Invoke-AppveyorInstall
-
-build_script:
-  - ps: Invoke-AppveyorBuild
-
-test_script:
-  - ps: Invoke-AppveyorTest -Purpose $env:Purpose
-
-after_test:
-  - ps: Invoke-AppVeyorAfterTest
-
-# Packaging
-on_finish:
-  - ps: if ($env:Purpose -eq 'ElevatedPesterTests_xUnit_Packaging'){ Invoke-AppveyorFinish }