Make it possible to run the same test against multiple URIs

We sometimes need to duplicate tests in order to run the same test against multiple URIs (especially in rule exclusion tests). It would be great if we could simply specify a list of URIs and reuse the test data for each of them. I think we could add a new field called uris that takes a list, so we'd have both uri (single URI, backwards compatibility) and uris (multiple URIs).