Remove unused subroutine
Add note at the top of t/test_feed_download.t to explain how to regenerate the test data (just like in t/test_crawler.t); make file executable and prepend the Perl shebang
When dumping data for unit tests to a file, make Data::Dumper sort the hash keys so that the order of those keys will be the same on each run; this should make it easier to evaluate the crawler / extractor changes in the Git commit diff
Remove mentions of "top 500 words" in t/test_single_crawler_download.t and its data file too because "top 500 words" are not being tested for quite some time (AFAIK because of the migration to Solr)