Update VCR to see errors disguised by "UnusedHTTPInteractionError"

VCR fixed by: https://github.com/vcr/vcr/pull/336
discussion: http://talk.manageiq.org/t/travis-vcr-cassettes-and-unused-http-interactions/97/2
Merge pull request #291 from brandondunne/upgrade_vcr

Update VCR to see errors disguised by "UnusedHTTPInteractionError"