Fleshed out entity classes and created command to create student

BrightGlimmer.Domain/Entity.cs

@@ -1,15 +1,21 @@
-using System;
+using Newtonsoft.Json;
+using System;
 using System.Collections.Generic;
+using System.ComponentModel.DataAnnotations;
 using System.Text;
 
 namespace BrightGlimmer.Domain
 {
     public class Entity
     {
-        public Guid Id { get; set; }
-        public bool IsDeleted { get; set; }
-        public DateTime CreatedDate { get; set; }
-        public DateTime ModifiedDate { get; set; }
+        [Key]
+        public Guid Id { get; private set; }
+        [JsonIgnore]
+        public bool IsDeleted { get; protected set; }
+        [JsonIgnore]
+        public DateTime CreatedDate { get; protected set; }
+        [JsonIgnore]
+        public DateTime ModifiedDate { get; protected set; }
 
         public Entity()
         {
@@ -17,6 +23,15 @@ namespace BrightGlimmer.Domain
             CreatedDate = DateTime.UtcNow;
             ModifiedDate = DateTime.UtcNow;
         }
-    }
 
+        protected void Delete()
+        {
+            IsDeleted = true;
+        }
+
+        protected void MarkModified()
+        {
+            ModifiedDate = DateTime.UtcNow;
+        }
+    }
 }