VCR

I used the VCR gem to record the HTTP requests we make to the OAI server and play them back for the integration tests. This now means that our tests don't need to connect to our OAI server, but if we ever want to explicitly test against our server it'll be easy to do. This also means the travis build now passes.

Bonus: Upgrade to rspec syntax to get rid of deprecation warnings, bug fix to be compatible with jruby