Try to workaround warnings from InspectCode

Author: bkoelman

Diff for: Directory.Build.props

@@ -21,6 +21,10 @@
     <AdditionalFiles Include="$(MSBuildThisFileDirectory)CSharpGuidelinesAnalyzer.config" Visible="False" />
   </ItemGroup>
 
+  <ItemGroup>
+    <SourceRoot Include="$(MSBuildThisFileDirectory)/"/>
+  </ItemGroup>
+
   <PropertyGroup Condition="'$(CI)' != ''">
     <ContinuousIntegrationBuild>true</ContinuousIntegrationBuild>
   </PropertyGroup>