Failed attempt to get an integration test going for the twine scraper

Records some of the interactions with twine.cc (but not all) through a proxy server. Records wunderground requests fine. Test passed a few times, but most of the time it didn't, so it's unreliable. Looks like it's due to the proxy server using threads, while vcr isn't threadsafe. 

PR just for reference in issue #5, in case somebody has any other ideas on how to get this to work.