Update prepare_data.sh

prepare_data.sh

 #!/bin/bash
 
+echo "-------------------------------------------"
+echo "Acceptable Use Policy and Conditions of Use"
+echo "-------------------------------------------"
+echo "Acceptable Use Policy and Conditions of Use (https://dataportal.europdx.eu/about/aup)"
+echo "have to be accepted before downloading and using EurOPDX data."
+
+read -p "Do you accept the Acceptable Use Policy and Conditions of Use? [yes/no]" choice
+case "$choice" in 
+  yes|Yes ) echo "AUP accepted.";;
+  * ) echo "AUP not accepted. Exiting." ;exit 0;;
+esac
+
+
 set -x
 
 # Copy graph.tgz