Update SDK to .NET 5 Preview 6.

Author: bgrainger

.github/workflows/publish-package.yml

@@ -22,7 +22,7 @@ jobs:
     - name: Set up .NET Core
       uses: actions/setup-dotnet@v1
       with:
-        dotnet-version: 5.0.100-preview.5.20279.10
+        dotnet-version: 5.0.100-preview.6.20318.15
 
     - name: Restore
       run: dotnet restore

appveyor.yml

@@ -11,7 +11,7 @@ install:
   # The following can be used to install a custom version of .NET Core
   - ps: Invoke-WebRequest -Uri "https://raw.githubusercontent.com/dotnet/cli/master/scripts/obtain/dotnet-install.ps1" -OutFile "install-dotnet.ps1"
   - ps: .\install-dotnet.ps1 -Version 3.1.301 -InstallDir "dotnetcli"
-  - ps: .\install-dotnet.ps1 -Version 5.0.100-preview.5.20279.10 -InstallDir "dotnetcli"
+  - ps: .\install-dotnet.ps1 -Version 5.0.100-preview.6.20318.15 -InstallDir "dotnetcli"
 build_script:
 - dotnet --info
 before_test:

azure-pipelines.yml

@@ -1,5 +1,5 @@
 variables:
-  DotNetCoreSdkVersion: '5.0.100-preview.5.20279.10'
+  DotNetCoreSdkVersion: '5.0.100-preview.6.20318.15'
   NUGET_PACKAGES: '$(Pipeline.Workspace)/.nuget/packages'
 
 jobs: