cleanup.

Author: codemzs

src/Microsoft.ML.TimeSeries/Forecast.cs

@@ -1,8 +1,9 @@
-using Microsoft.ML.Runtime;
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using Microsoft.ML.Runtime;
 using Microsoft.ML.Runtime.Data;
-using System;
-using System.Collections.Generic;
-using System.Text;
 
 namespace Microsoft.ML.TimeSeries
 {