Changes to work with airflow dag

[chriscauley]

When I designed this I built it with cli usage in mind. There's a few tweaks I need to make to have this work inside a python script.

• check_feeds should return results
• Ability to disable cache - I don't think this should run with the cache on in production. Make it so setting the cache_dir to 0 disables caching.
• Move stdout (print calls) to the __main__ file.
• Move --output flag to the main file