Two simple tests and convert one func to use VCR
::get_content_for_code works with test
Abstract out getting a NAICS page (whether VCR-stored or live GET) from the act of parsing the content of said page
Remove some extraneous/irrelevant comments
Got response for 4-digit code
Add some more caching tests and one failing one for Lou's 5-digit use case
Added note on using VCR - closes #3