bumping to Plek 1.0.0

Also updating all tests to use dev.gov.uk (test.gov.uk is not required)
bumping slimmer to 3.9.5
changing assets to static
Set sensible defaults if ENV vars are not found
Upgrade Rails to 3.2.11
Revert unintended changes to Gemfile.lock
Merge remote branch 'origin/bump-plek-rebased'