Bump rails to 4.1.4

This picks up the latest security fixes.
Merge pull request #28 from alphagov/bump-rails-to-4.1.4

Bump rails to 4.1.4
Validate requests against GOV.UK SSO using tokens
Merge pull request #29 from alphagov/sso-integration

Token-based authentication using GOV.UK SSO
Reject any manual or section with HTML text fields

For each submission, the attributes are crawled recursively and
each found text-field is piped through the 'sanitize' gem, so that
the HTML can be detected.