[release/3.1.2xx] Update dependencies from dotnet/arcade

[dotnet-maestro]

This pull request updates the following dependencies

From https://github.com/dotnet/arcade

• Build: 20191127.5
• Date Produced: 11/27/2019 11:33 PM
• Commit: 99c6b59a8afff97fe891341b39abe985f1d3c565
• Branch: refs/heads/release/3.x
• Updates:
  • Microsoft.DotNet.Arcade.Sdk -> 1.0.0-beta.19577.5
  • Microsoft.DotNet.Helix.Sdk -> 2.0.0-beta.19577.5
  • Microsoft.DotNet.SignTool -> 1.0.0-beta.19577.5

[dotnet-maestro]

Auto-Merge Status

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

• ✔️ Standard Merge Policies Succeeded - Successful checks: 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 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), dotnet-sdk-public-ci (Build Ubuntu_16_04 Build_Release), dotnet-sdk-public-ci (Build Darwin Build_Release), dotnet-sdk-public-ci (Build Ubuntu_16_04 Build_Debug), dotnet-sdk-public-ci (Build Darwin Build_Debug)
• ✔️ Standard Merge Policies Succeeded - No reviews have requested changes.