public async Task PostALonganizaShouldReturSuccess()
        {
            using (var server = TestServer.Create<TestStartup>())
            {
                var longanizaCatalana = new Longaniza { Name = "catalana", Price = 20, SelledBy = new List<Shop> { new Shop { Id = 6, Name = "Carniceria pepa" } } };

                HttpResponseMessage response = 
                    await server.HttpClient
                    .PostAsync<Longaniza>("api/longanizas", longanizaCatalana, new JsonMediaTypeFormatter());

                response.IsSuccessStatusCode.Should().BeTrue();
            }
        }
 public IHttpActionResult AddLonganiza(Longaniza newLonganiza)
 {
     return Ok();
 }