Add some missing copyright

.gitlab-ci.yml

 ###############################################################################
-# (c) Copyright 2018 CERN for the benefit of the LHCb Collaboration           #
+# (c) Copyright 2020 CERN for the benefit of the LHCb Collaboration           #
 #                                                                             #
 # This software is distributed under the terms of the GNU General Public      #
 # Licence version 3 (GPL Version 3), copied verbatim in the file "COPYING".   #

doc/Makefile

+###############################################################################
+# (c) Copyright 2020 CERN for the benefit of the LHCb Collaboration           #
+#                                                                             #
+# This software is distributed under the terms of the GNU General Public      #
+# Licence version 3 (GPL Version 3), copied verbatim in the file "COPYING".   #
+#                                                                             #
+# In applying this licence, CERN does not waive the privileges and immunities #
+# granted to it by virtue of its status as an Intergovernmental Organization  #
+# or submit itself to any jurisdiction.                                       #
+###############################################################################
 # Minimal makefile for Sphinx documentation
 #
 

doc/conf.py

+###############################################################################
+# (c) Copyright 2020 CERN for the benefit of the LHCb Collaboration           #
+#                                                                             #
+# This software is distributed under the terms of the GNU General Public      #
+# Licence version 3 (GPL Version 3), copied verbatim in the file "COPYING".   #
+#                                                                             #
+# In applying this licence, CERN does not waive the privileges and immunities #
+# granted to it by virtue of its status as an Intergovernmental Organization  #
+# or submit itself to any jurisdiction.                                       #
+###############################################################################
 # Configuration file for the Sphinx documentation builder.
 #
 # This file only contains a selection of the most common options. For a full