[master] Update dependencies from dotnet/arcade

[dotnet-maestro[bot]]

This pull request updates the following dependencies

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

• Subscription: 511f7461-8f9c-452e-fa2a-08d7a4f216c0
• Build: 20200528.4
• Date Produced: 5/28/2020 4:10 PM
• Commit: 96c65ad967d2abbbd8e770ba752a6b64255ec669
• Branch: refs/heads/master
• Updates:
  • Microsoft.DotNet.Arcade.Sdk: from 5.0.0-beta.20261.9 to 5.0.0-beta.20278.4
  • Microsoft.DotNet.Helix.Sdk: from 5.0.0-beta.20261.9 to 5.0.0-beta.20278.4
• Updates to .NET SDKs:
  • Updates tools.dotnet to 5.0.100-preview.6.20266.3

[dotnet-maestro[bot]]

Auto-Merge Status

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

• ✔️ All Checks Successful Succeeded - Successful checks: corefxlab-ci, corefxlab-ci (build Innerloop Ubuntu16.04 x64_Debug), corefxlab-ci (build Innerloop Ubuntu16.04 x64_Release), corefxlab-ci (build Innerloop OSX x64_Debug), corefxlab-ci (build Innerloop OSX x64_Release), corefxlab-ci (build Innerloop Windows_NT x64_Debug), corefxlab-ci (build Innerloop Windows_NT x64_Release)