add supplier attributes

AB.Contracts/CommunicationType.cs

@@ -0,0 +1,19 @@
+using System.Runtime.Serialization;
+
+namespace AB.Contracts
+{
+    public enum CommunicationType
+    {
+        [EnumMember(Value = "Email")]
+        Email,
+
+        [EnumMember(Value = "Postal")]
+        Postal,
+
+        [EnumMember(Value = "Phone")]
+        Phone,
+
+        [EnumMember(Value = "Fax")]
+        Fax
+    }
+}