docs: contributing: happy new year, update copyright
@@ -180,7 +180,7 @@ When you commit your local changes in your repository (before to push to Github)
```
/* Fluent Bit
* ==========
- * Copyright (C) 2019 The Fluent Bit Authors
+ * Copyright (C) 2019-2020 The Fluent Bit Authors
* Copyright (C) 2015-2018 Treasure Data Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
