Add Devel::Cover::Report::Coveralls dependency which would help uploading test coverage results to Coveralls.io
Ignore Devel::Cover output
Add helper script to generate various types of test coverage reports
Run test suite under Devel::Cover, upload results to https://coveralls.io/r/berkmancenter/mediacloud
Add test coverage badge [ci skip]
Merge branch 'master' into devel_cover

Conflicts:
	README.mdown
	cpanfile
fix the coverage badge by switching to the difference branch in the URL.
Remove MediaWords::Tagger::SIP (because it's not being used - or even referenced - anywhere), data files, and package's dependency BerkeleyDB
Remove stop words generator and its dependencies "DB_File" and "DBM_Filter"; dependencies use BerkeleyDB as a backend (and we've removed that in previous commit 8a3d2f7a629f7bd03243f4d66c2b048135becf7f), stop words generator is not being used at the moment, and it could be resurrected from Git's history if needed
Move "extract_corpus_from_wikipedia.pl" helper script to archive, remove its dependencies from "cpanfile"
Remove "coverage_with_carton.sh" script because "run_test_suite_for_devel_cover.sh" script does that already
Remove "Text::Ngrams" dependency because the only script that uses it is in the archive (script_archive/mediawords_test_ngrams.pl)
Remove "URI::Find" from a *direct* list of dependencies (it's still required by Catalyst though)
Remove private subroutine which is not used anywhere in the code
Move script "add_spider_blog_posting_downloads.pl" to archive because it doesn't seem like it's being used anymore
Remove old database migrations
Remove another private subroutine which is not used anywhere in the code
Move multiple blog spider related scripts to archive
Remove one more private subroutine which is not used anywhere in the code
Remove unused variable