make sure test config is passed

Rx.NET/Source/build-new.ps1

@@ -82,7 +82,7 @@ else
 {
 	$dotnet = "$env:ProgramFiles\dotnet\dotnet.exe"
 	#.\packages\JetBrains.dotCover.CommandLineTools\tools\dotCover.exe cover /targetexecutable="c:\program files\dotnet\dotnet.exe" /targetworkingdir=".\Tests.System.Reactive" /targetarguments="test --no-build --filter:SkipCI!=true" /output=.\testResults.dvcr /Filters="+:module=System.Reactive;+:module=Microsoft.Reactive.Testing;+:module=System.Reactive.Observable.Aliases;-:type=Xunit*" /DisableDefaultFilters
-	.\packages\JetBrains.dotCover.CommandLineTools\tools\dotCover.exe analyze /targetexecutable="$dotnet" /targetworkingdir="$testDirectory" /targetarguments="test --no-build --filter:SkipCI!=true" /ReportType=DetailedXML /output="$outputFile" /Filters="+:module=System.Reactive;+:module=Microsoft.Reactive.Testing;+:module=System.Reactive.Observable.Aliases;-:type=Xunit*" /DisableDefaultFilters /HideAutoProperties /ReturnTargetExitCode
+	.\packages\JetBrains.dotCover.CommandLineTools\tools\dotCover.exe analyze /targetexecutable="$dotnet" /targetworkingdir="$testDirectory" /targetarguments="test -c $configuration --no-build --filter:SkipCI!=true" /ReportType=DetailedXML /output="$outputFile" /Filters="+:module=System.Reactive;+:module=Microsoft.Reactive.Testing;+:module=System.Reactive.Observable.Aliases;-:type=Xunit*" /DisableDefaultFilters /HideAutoProperties /ReturnTargetExitCode
 
 	.\packages\ReportGenerator\tools\ReportGenerator.exe -reports:"$outputFile" -targetdir:"$outputPath"
     &"$outPutPath/index.htm"