Fix other NewCrawler invocations

cmd/crawl/crawl_test.go

@@ -63,6 +63,7 @@ func TestCrawl(t *testing.T) {
 		scope,
 		crawl.FetcherFunc(fetch),
 		crawl.HandleRetries(crawl.FollowRedirects(crawl.FilterErrors(saver))),
+		nil,
 	)
 	if err != nil {
 		t.Fatal(err)

cmd/links/links.go

@@ -52,6 +52,7 @@ func main() {
 		scope,
 		crawl.FetcherFunc(http.Get),
 		crawl.HandleRetries(crawl.FollowRedirects(crawl.FilterErrors(crawl.HandlerFunc(extractLinks)))),
+		nil,
 	)
 	if err != nil {
 		log.Fatal(err)