port passphrase change test to rails integration
delete passphrase change feature (it's ported)
port passphrase reset test to rails integration
delete passphrase reset feature (it's ported)
port passphrase expiry test to rails integration
delete passphrase expiry feature (it's ported)
move 'assert_response_contains' helper to a better place
inline some test helpers, extract others
Merge pull request #141 from alphagov/port-cucumber-password-features-to-rails-integration

Port cucumber password features to rails integration