Handcrafted VCR cassettes, made with love and care for passing tests
Update HoldingRequest creation feature for clarity
Remove Poltergeist from the dependencies since it seems incompatible with VCR

- Instead of running cucumber tests with Poltergeist and PhantomJS, use Selenium as the driver, Firefox as the browser (by default) and XVFB for headless GUI support in Travis
- To remove Poltergeist and its dependencies, update the bundled gems and lock them in
Merge branch 'feature/fix-travis' into development