Added --user-list flag to update_db_schema.bash to list the username of the database owner (as set in config).
Added --user-list flag to update_db_schema.bash to list the username of the
database owner (as set in config).

This is useful for various automatic sanity checks, such as checking that the
changesets are applied with the same user as the application/tests will use.

yak/virtualmeet-vcs-tools,yak/virtualmeet-vcs-tools