fix build

Author: MarcoRossignoli

test/Directory.Build.props

@@ -1,5 +1,6 @@
 <?xml version="1.0" encoding="utf-8"?>
 <Project>
+  <Import Project="$([MSBuild]::GetPathOfFileAbove('Directory.Build.props', '$(MSBuildThisFileDirectory)../'))" />
   <PropertyGroup>
     <IsTestProject>true</IsTestProject>
   </PropertyGroup>