clean(error-test): remove unused ns

Author: jaredcnance

test/JsonApiDotNetCoreExampleTests/Acceptance/Extensibility/CustomErrorTests.cs

@@ -1,11 +1,7 @@
-using DotNetCoreDocs;
-using JsonApiDotNetCoreExample;
-using DotNetCoreDocs.Writers;
 using Newtonsoft.Json;
 using JsonApiDotNetCore.Internal;
 using JsonApiDotNetCore.Serialization;
 using Xunit;
-using System.Diagnostics;
 
 namespace JsonApiDotNetCoreExampleTests.Acceptance.Extensibility
 {
@@ -14,8 +10,6 @@ public class CustomErrorTests
         [Fact]
         public void Can_Return_Custom_Error_Types()
         {
-            // while(!Debugger.IsAttached) { bool stop = false; }
-
             // arrange
             var error = new CustomError("507", "title", "detail", "custom");
             var errorCollection = new ErrorCollection();