Fix warning about GTIDs when taking dumps from Aurora #1
Description
When backing up Aurora,
Warning: A partial dump from a server that has GTIDs will by default include the GTIDs of all transactions, even those that changed suppressed parts of the database. If you don't want to restore GTIDs, pass --set-gtid-purged=OFF. To make a complete dump, pass --all-databases --triggers --routines --events.
If we provide an option to --set-gtid-purged= OFF, this should silence warning. GTIDs are used in replication. It's unlikely they'd be needed in a simple mysql dump.