[master] Update dependencies from nuget/nuget.client

[dotnet-maestro]

This pull request updates the following dependencies

From https://github.com/NuGet/NuGet.Client

• Subscription: be39118f-8347-4151-a885-08d7219800a1
• Build: 5.6.0.6478
• Date Produced: 2/27/2020 1:21 AM
• Commit: 64f2febf7d1de8b0228eca5afed97a96c5a30bba
• Branch: refs/heads/dev
• Updates:
  • NuGet.Build.Tasks -> 5.6.0-preview.1.6478

[dotnet-maestro]

Auto-Merge Status

This pull request has not been merged because Maestro++ is waiting on the following merge policies.

• ❌ All Checks Successful Unsuccessful checks: dotnet-sdk-public-ci, dotnet-sdk-public-ci (Build Windows_NT_TestAsTools Build_Debug)

[ViktorHofer]

/azp run dotnet-sdk-public-ci

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).

[dotnet-maestro]

Auto-Merge Status

This pull request has been merged because the following merge policies have succeeded.

• ✔️ All Checks Successful Succeeded - Successful checks: license/cla, dotnet-sdk-public-ci, dotnet-sdk-public-ci (Build Windows_Perf_CI_FullFramework Build_Release), dotnet-sdk-public-ci (Build Linux_Perf_CI Build_Release), dotnet-sdk-public-ci (Build Windows_Perf_CI Build_Release), dotnet-sdk-public-ci (Build Darwin Build_Release), dotnet-sdk-public-ci (Build Darwin Build_Debug), dotnet-sdk-public-ci (Build Ubuntu_16_04 Build_Release), dotnet-sdk-public-ci (Build Ubuntu_16_04 Build_Debug), dotnet-sdk-public-ci (Build Windows_NT_TestAsTools Build_Debug), dotnet-sdk-public-ci (Build Windows_NT_FullFramework Build_Release), dotnet-sdk-public-ci (Build Windows_NT Build_Release), dotnet-sdk-public-ci (Build Windows_NT_FullFramework Build_Debug), dotnet-sdk-public-ci (Build Windows_NT Build_Debug), WIP