refactoring

Yavsc.Abstract/Authentication/OAuthenticator.cs

@@ -1,8 +1,6 @@
 
 using System;
 using System.Threading.Tasks;
-using System.Linq;
-using System.Collections;
 using System.Collections.Generic;
 using System.Net;
 using System.Text;

Yavsc.Abstract/Billing/IBillable.cs

@@ -5,7 +5,7 @@ using Yavsc.Services;
 namespace Yavsc.Billing
 {
     public interface IBillable {
-        string GetDescription ();
+        string Description { get; }
         List<IBillItem> GetBillItems();
         long Id { get; set; }