v1.12.0

• Fix rake dev:prime now that Suspenders-generated apps require some ENV
  variables to be set.
• Ensure EMAIL_RECIPIENTS is set on staging.
• Clear ActionMailer deliveries before every test.
• Include New Relic configuration file.
• Add Formulaic gem for integration testing HTML forms.
• Set up the Segment.io adapter for analytics and event tracking through
  services such as Google Analytics and Intercom.
• Prepare staging and production environments to serve static assets through a
  CDN.