refs and cleanup

src/Directory.Build.props

@@ -13,6 +13,7 @@
     <NuGetAuditMode>all</NuGetAuditMode>
     <NuGetAuditLevel>low</NuGetAuditLevel>
     <TreatWarningsAsErrors>true</TreatWarningsAsErrors>
+    <EnforceCodeStyleInBuild>true</EnforceCodeStyleInBuild>
   </PropertyGroup>
   <ItemGroup>
     <None Include="$(MSBuildThisFileFullPath)\..\..\license.txt"