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

[dotnet-maestro]

This pull request updates the following dependencies

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

• Subscription: 9f2ba0f1-e8d3-4958-c5dc-08d76fa9c820
• Build: 20200331.15
• Date Produced: 4/1/2020 5:42 AM
• Commit: ffab087b73506f6622eff69e087efcb557efeef4
• Branch: refs/heads/release/3.1
• Updates:
  • Microsoft.AspNetCore.DeveloperCertificates.XPlat -> 3.1.4-servicing.20181.15

[dotnet-maestro]

Auto-Merge Status

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

• ✔️ Standard Merge Policies Succeeded - Successful checks: .NET Core CLI CI, .NET Core CLI CI (Build Linux Build_Rhel_7_2_Release_x64), .NET Core CLI CI (Build Linux Build_Ubuntu_14_04_Release_x64), .NET Core CLI CI (Build Windows_NT Build_Release_x64), .NET Core CLI CI (Build Windows_NT Build_DropSuffix_Release_x64), .NET Core CLI CI (Build Windows_NT Build_ES_Debug_x64), .NET Core CLI CI (Build Windows_NT Build_Debug_x86), .NET Core CLI CI (Build Linux Build_LinuxPortable_NoSuffix_Release_x64), .NET Core CLI CI (Build Linux Build_LinuxPortable_Release_x64), .NET Core CLI CI (Build Linux Build_Linux_musl_Debug_x64), .NET Core CLI CI (Build Linux Build_Rhel_6_Debug_x64), .NET Core CLI CI (Build Linux Build_Debian_jessie_Debug_x64), .NET Core CLI CI (Build Linux Build_CentOS_7_1_Debug_x64), .NET Core CLI CI (Build Linux Build_OpenSUSE_42_3_Debug_x64), .NET Core CLI CI (Build Linux Build_Fedora_27_Debug_x64), .NET Core CLI CI (Build Linux Build_Ubuntu_18_04_Debug_x64), .NET Core CLI CI (Build Linux Build_Ubuntu_16_04_Debug_x64), .NET Core CLI CI (Build Darwin Build_Release)
• ✔️ Standard Merge Policies Succeeded - No reviews have requested changes.