Moved the credential files into their own folder.

Credentials/CredentialPackage.cs

@@ -0,0 +1,15 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace NSspi
+{
+    public enum SecurityPackage
+    {
+        Negotiate = 0,
+        Kerberos = 1,
+        NTLM = 2
+    }
+}