Disable shadow copying during xUnit tests

Author: jasonmalinowski

src/Microsoft.NuGet.Build.Tasks.Tests/Microsoft.NuGet.Build.Tasks.Tests.csproj

@@ -73,6 +73,7 @@
     </ProjectReference>
   </ItemGroup>
   <ItemGroup>
+    <None Include="app.config" />
     <None Include="Json\analyzers.json" />
     <None Include="Json\FluentAssertions.lock.json" />
     <None Include="Json\FluentAssertionsAndWin10.lock.json" />
@@ -106,4 +107,4 @@
   <Target Name="AfterBuild">
   </Target>
   -->
-</Project>
+</Project>

src/Microsoft.NuGet.Build.Tasks.Tests/app.config

@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="utf-8"?>
+<configuration>
+  <appSettings>
+    <add key="xunit.shadowCopy" value="false"/>
+  </appSettings>
+</configuration>