Fixed warnings.

tests/CleanArchitecture.Tests/Core/Entities/ToDoItemMarkCompleteShould.cs

@@ -24,7 +24,7 @@ namespace CleanArchitecture.Tests.Core.Entities
 
             item.MarkComplete();
 
-            Assert.Equal(1, item.Events.Count());
+            Assert.Single(item.Events);
             Assert.IsType<ToDoItemCompletedEvent>(item.Events.First());
         }
     }

tests/CleanArchitecture.Tests/Integration/Data/EfRepositoryShould.cs

@@ -26,7 +26,7 @@ namespace CleanArchitecture.Tests.Integration.Data
             // Create a new options instance telling the context to use an
             // InMemory database and the new service provider.
             var builder = new DbContextOptionsBuilder<AppDbContext>();
-            builder.UseInMemoryDatabase()
+            builder.UseInMemoryDatabase("db")
                    .UseInternalServiceProvider(serviceProvider);
 
             return builder.Options;