Add slimmer to get header, footer, report-a-problem
Add rspec
Failing spec for viewing the need for a given slug
Start integration with metadata-api

This includes a hack (that will be refactored later) to include
the `govuk-client-url_arbiter` gem (so that we can reuse the JSON
client).
Render needs on the info page
GOV.UK rendering and styling of info page
Better signposting for the needs on the info page
Extend spec coverage

Spec now covers need acceptance criteria and justification
Info page: handle slugs without needs
Show 'page not found' if no info for slug

Until there are page stats available, there isn't anything meaningful to
show for a slug that doesn't come back with an artefact or needs.
Merge pull request #2 from alphagov/flip-the-page-needs

'Flip the page': displaying user needs