Add MongoTestCollection to OrganizationUnitRepository_Tests class.

modules/identity/test/Volo.Abp.Identity.MongoDB.Tests/Volo/Abp/Identity/MongoDB/OrganizationUnitRepository_Tests.cs

@@ -4,6 +4,7 @@ using System.Text;
 
 namespace Volo.Abp.Identity.MongoDB
 {
+    [Collection(MongoTestCollection.Name)]
     public class OrganizationUnitRepository_Tests : OrganizationUnitRepository_Tests<AbpIdentityMongoDbTestModule>
     {
     }