Add Expiration Date To Organization Invite Emails (#1466)

* Added an expiration date to the organization user invite email

* Added a period

* moved property assignment around

* fixed date offset

src/Core/Models/Business/ExpiringToken.cs

@@ -0,0 +1,16 @@
+using System;
+
+namespace Bit.Core.Models.Business
+{
+    public class ExpiringToken
+    {
+        public readonly string Token; 
+        public readonly DateTime ExpirationDate; 
+
+        public ExpiringToken(string token, DateTime expirationDate)
+        {
+            Token = token;
+            ExpirationDate = expirationDate;
+        }
+    }
+}