Bump Microsoft.NET.Test.Sdk from 17.12.0 to 18.4.0#326

dependabot[bot] wants to merge 1 commit intomainrpgrca/objects-course-2:mainfrom

dependabot/nuget/CSharp/C2-ElevatorExercise/ElevatorExercise.UnitTests/Microsoft.NET.Test.Sdk-18.4.0rpgrca/objects-course-2:dependabot/nuget/CSharp/C2-ElevatorExercise/ElevatorExercise.UnitTests/Microsoft.NET.Test.Sdk-18.4.0Copy head branch name to clipboard