fix(repository-override-test): invalid syntax

Author: jaredcnance

test/JsonApiDotNetCoreExampleTests/Acceptance/Extensibility/RepositoryOverrideTests.cs

@@ -2,7 +2,7 @@
 using System.Net.Http;
 using System.Threading.Tasks;
 using Microsoft.AspNetCore.Hosting;
-using Microsoft.AspNetCore.TestHost;]
+using Microsoft.AspNetCore.TestHost;
 using Xunit;
 using JsonApiDotNetCoreExample.Data;
 using JsonApiDotNetCoreExampleTests.Startups;