public async Task TestDeleteCurrency()
        {
            List <Currencies> currenciesToAdd = new List <Currencies>();

            currenciesToAdd.Add(new Currencies()
            {
                Exponent = 2,
                Symbol   = "&",
                Name     = "TestToDelete"
            });
            await AddCurrency(currenciesToAdd);

            var currencies = await currenciesController.GetCurrencies();

            await currenciesController.DeleteCurrencies(currencies.Value.First().Id);

            var test = await currenciesController.GetCurrencies(currencies.Value.First().Id.ToString());

            if (test.Value == null)
            {
                Assert.Pass();
            }
            else
            {
                Assert.Fail();
            }
        }