Nice addition, but can you modify it so it doesn't spit the "table doesn't exist" error out to the terminal? We're trying to clean up the test output at the moment.
Oh, and it should be this_table_does_not_exist (without the trailing s :-) )
Download csv URL with wrong query ... 2019-04-11 13:54:38,710: ERRORflask.app:failed to execute query ((with server cursor) for the server #4 - CONN:3783391 (query-id: 5309318):
error message:ERROR: relation "this_table_does_not_exists" does not exist