Installing faraday 0.8.9 because travis-artifacts will install an incompatible version

https://github.com/travis-ci/travis-artifacts/issues/23

We can remove this once the travis-artifacts gem in updated.
Merge pull request #11 from modcloth-labs/install-faraday-0.8.9

Installing faraday 0.8.9 because travis-artifacts will install an incomp...