Try fix from microsoft/vstest#2218 (comment)

The previous version failed on the Github Actions 'windows-2019' environment with following log:
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##[warning]Startup.cs(104,13): warning CS0618: 'IHostingEnvironment' is obsolete: 'This type is obsolete and will be removed in a future version. The recommended alternative is Microsoft.AspNetCore.Hosting.IWebHostEnvironment.' [D:\a\elm-fullstack\elm-fullstack\implement\PersistentProcess\PersistentProcess.WebHost\PersistentProcess.WebHost.csproj]
Startup.cs(28,35): warning ASP0000: Calling 'BuildServiceProvider' from application code results in an additional copy of singleton services being created. Consider alternatives such as dependency injecting services as parameters to 'Configure'. [D:\a\elm-fullstack\elm-fullstack\implement\PersistentProcess\PersistentProcess.WebHost\PersistentProcess.WebHost.csproj]
##[warning]TestWebHost.cs(724,27): warning CS0649: Field 'TestWebHost.Web_host_propagates_HTTP_headers_Response_Entry.name' is never assigned to, and will always have its default value null [D:\a\elm-fullstack\elm-fullstack\implement\PersistentProcess\PersistentProcess.Test\PersistentProcess.Test.csproj]
##[warning]TestWebHost.cs(726,29): warning CS0649: Field 'TestWebHost.Web_host_propagates_HTTP_headers_Response_Entry.values' is never assigned to, and will always have its default value null [D:\a\elm-fullstack\elm-fullstack\implement\PersistentProcess\PersistentProcess.Test\PersistentProcess.Test.csproj]
Test run for D:\a\elm-fullstack\elm-fullstack\implement\PersistentProcess\PersistentProcess.Test\bin\Debug\netcoreapp3.0\PersistentProcess.Test.dll(.NETCoreApp,Version=v3.0)
Microsoft (R) Test Execution Command Line Tool Version 16.3.0
Copyright (c) Microsoft Corporation.  All rights reserved.

Starting test execution, please wait...

A total of 1 test files matched the specified pattern.
Testhost process exited with error: A fatal error occurred, the required library hostfxr.dll could not be found.
If this is a self-contained application, that library should exist in [D:\a\elm-fullstack\elm-fullstack\implement\PersistentProcess\PersistentProcess.Test\bin\Debug\netcoreapp3.0\].
If this is a framework-dependent application, install the runtime in the default location [C:\Program Files\dotnet] or use the DOTNET_ROOT environment variable to specify the runtime location.
. Please check the diagnostic logs for more information.
Results File: D:\a\elm-fullstack\elm-fullstack\implement\PersistentProcess\PersistentProcess.Test\TestResults\runneradmin_fv-az75_2019-10-30_10_14_51.trx
Test Run Aborted.

##[error]Process completed with exit code 1.

implement/PersistentProcess/PersistentProcess.Test/PersistentProcess.Test.csproj

@@ -10,7 +10,7 @@
     <PackageReference Include="Appveyor.TestLogger" Version="2.0.0" />
     <PackageReference Include="FluentAssertions" Version="5.5.0" />
     <PackageReference Include="Microsoft.AspNetCore.TestHost" Version="3.0.0" />
-    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="16.3.0" />
+    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="16.2.0" />
     <PackageReference Include="morelinq" Version="3.0.0" />
     <PackageReference Include="MSTest.TestAdapter" Version="2.0.0" />
     <PackageReference Include="MSTest.TestFramework" Version="2.0.0" />