[release/3.1] Update dependencies from dotnet/arcade (#41316)
[release/3.1] Update dependencies from dotnet/arcade (#41316)

* Update dependencies from https://github.com/dotnet/arcade build 20190924.3

- Microsoft.DotNet.XUnitExtensions - 2.4.1-beta.19474.3
- Microsoft.DotNet.XUnitConsoleRunner - 2.5.1-beta.19474.3
- Microsoft.DotNet.VersionTools.Tasks - 1.0.0-beta.19474.3
- Microsoft.DotNet.ApiCompat - 1.0.0-beta.19474.3
- Microsoft.DotNet.Arcade.Sdk - 1.0.0-beta.19474.3
- Microsoft.DotNet.Build.Tasks.Configuration - 1.0.0-beta.19474.3
- Microsoft.DotNet.Build.Tasks.Feed - 2.2.0-beta.19474.3
- Microsoft.DotNet.Build.Tasks.Packaging - 1.0.0-beta.19474.3
- Microsoft.DotNet.CodeAnalysis - 1.0.0-beta.19474.3
- Microsoft.DotNet.CoreFxTesting - 1.0.0-beta.19474.3
- Microsoft.DotNet.GenAPI - 1.0.0-beta.19474.3
- Microsoft.DotNet.GenFacades - 1.0.0-beta.19474.3
- Microsoft.DotNet.Helix.Sdk - 2.0.0-beta.19474.3
- Microsoft.DotNet.RemoteExecutor - 1.0.0-beta.19474.3

* Update NuGet.config

BrennanConroy/corefx,BrennanConroy/corefx,BrennanConroy/corefx