add check_job_error_rate to error out topic if the fetch_link or extract_story_links error rates are too high; add some constants
add check_job_error_rate to error out topic if the fetch_link or extract_story_links error rates are too high; add some constants

berkmancenter/mediacloud,berkmancenter/mediacloud,berkmancenter/mediacloud,berkmancenter/mediacloud,berkmancenter/mediacloud