public void Test_DeleteOne_DeletesOneCopy()
{
Copy newCopy1 = new Copy ("New", 1, new DateTime(2016, 7, 25), new DateTime(2016, 8, 25));
Copy newCopy2 = new Copy ("Worn & Torn", 2, new DateTime(2016, 7, 25), new DateTime(2016, 8, 25));
newCopy1.Save();
newCopy2.Save();
List<Copy> newList = Copy.GetAll();
newCopy1.DeleteOne();
List<Copy> resultList = Copy.GetAll();
List<Copy> testList = new List<Copy> {newCopy2};
Assert.Equal(testList, resultList);
}