Update Capybara and use Poltergeist instead of capybara webkit
Use poltergeist in integration tests. Add assertion helper
Fix integration tests now they use poltergeist
Give an explicit id to the edition edit form

Ensuring that new forms do not get rendered with the same id, stopping `publication.js`
from submitting the wrong form.
Disable CSS animations. Individually require CSS files
Avoid searching the DOM twice
Explain disabling CSS animations
Merge pull request #180 from alphagov/fix-integration-tests

Fix integration tests