more robust handling of bad urls
more robust handling of bad urls

mchelen/project-open-data-dashboard,albertcrowley/project-open-data-dashboard,dhootha/project-open-data-dashboard,albertcrowley/project-open-data-dashboard,mchelen/project-open-data-dashboard,dhootha/project-open-data-dashboard,dhootha/project-open-data-dashboard,mchelen/project-open-data-dashboard,albertcrowley/project-open-data-dashboard