Migrated to .NET Core 2.

Sample/Models/ManageViewModels/TwoFactorAuthenticationViewModel.cs

@@ -0,0 +1,17 @@
+using System;
+using System.Collections.Generic;
+using System.ComponentModel.DataAnnotations;
+using System.Linq;
+using System.Threading.Tasks;
+
+namespace Sample.Models.ManageViewModels
+{
+    public class TwoFactorAuthenticationViewModel
+    {
+        public bool HasAuthenticator { get; set; }
+
+        public int RecoveryCodesLeft { get; set; }
+
+        public bool Is2faEnabled { get; set; }
+    }
+}