Added ability to automatically track last modified and created timestamps for entities via an interface. DBContext will automatically update for us.

API/Entities/Volume.cs

@@ -1,12 +1,16 @@
-using System.Collections.Generic;
+using System;
+using System.Collections.Generic;
+using API.Entities.Interfaces;
 
 namespace API.Entities
 {
-    public class Volume
+    public class Volume : IEntityDate
     {
         public int Id { get; set; }
         public string Number { get; set; }
         public ICollection<MangaFile> Files { get; set; }
+        public DateTime Created { get; set; }
+        public DateTime LastModified { get; set; }
 
         // Many-to-Many relationships
         public Series Series { get; set; }