Get a green build against ruby 2.0.0

I added ruby 2.0.0 to the travis CI build and it's failing with a handful of failures:

https://travis-ci.org/vcr/vcr/jobs/5228667/#L194

@Jacobkg, can you take a stab at this?  I assigned it to you but feel free to re-assign off of yourself if you aren't able to get to it or would rather work on something else.