Updating copyright notices for 2020.

[ROCm/rccl commit: 20fa04d9b6]

projects/rccl/test/test_GroupCalls.cpp

@@ -1,5 +1,5 @@
 /*************************************************************************
- * Copyright (c) 2019 Advanced Micro Devices, Inc. All rights reserved.
+ * Copyright (c) 2019-2020 Advanced Micro Devices, Inc. All rights reserved.
  *
  * See LICENSE.txt for license information
  ************************************************************************/