Merge pull request #19 from NYULibraries/chore/use-rspec-rails

Use RspecRails
Add the Cucumber::Rails gem and lock it in
Add the DatabaseCleaner gem and lock it in

Cucumber::Rails recommends installing DatabaseCleaner. Who are we to question that wisdom?
Add Cucumber::Rails files that were install via the Rails generator
Open up UserSession and don't attempt SSO when logging in
Add a basic login feature
Cucumber tests need to wear Coveralls
Come semantically correct

Capybara offers have_link so we should use it.
Remove unnecessary teaspoon backup config