add validates_timeliness gem
remove cucumbers that are no longer required
port old website user validation specs
add site_prism auth section to pages
validate uniqueness of email
use capybara have_content assertions
Improve readability of a cucumber test
add novalidate to sign in form
Updates free debt advice image on home page.
Fixing modernizr load path
Merge pull request #589 from moneyadviceservice/registration-validation

Registration validation
Move shared links to top of registration page
install devise shared links view
Style devise shared links
Allow heading tag helper to accept optional attrs
Allow heading tag helper to accept optional block
Apply accessible headings to views