re-include logging files in nuget package and add test

Author: drewcassidy

KSPBuildTools.csproj

@@ -38,7 +38,7 @@
     <None Include="KSPCommon.props" Pack="True" PackagePath="build/KSPBuildTools.props" />
     <None Include="KSPCommon.targets" Pack="True" PackagePath="build/KSPBuildTools.targets" />
     <None Include="README.md" Pack="True" PackagePath="/"/>
-    <None Include="include/*.cs" Pack="True" PackagePath="/build/include/"/>
+    <None Include="include/**/*.cs" Pack="True" PackagePath="/build/include/"/>
   </ItemGroup>
 
   <ItemGroup>

tests/plugin-mod-nuget/pluginModNuget.cs

@@ -0,0 +1,6 @@
+using KSPBuildTools;
+using UnityEngine;
+using HarmonyLib;
+using System.Collections.Generic;
+
+public class pluginModNuget { }