Add copyright header to Golang files

internal/metricAggregator/metricAggregator.go

@@ -1,3 +1,10 @@
+// Copyright (C) NHR@FAU, University Erlangen-Nuremberg.
+// All rights reserved. This file is part of cc-lib.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+// additional authors:
+// Holger Obermaier (NHR@KIT)
+
 package metricAggregator
 
 import (