Adds basic PA 404 handling

Render Rails default 404 page if a given PA doesn't exit
Merge branch 'master' into 404-redirect

* master: (73 commits)
  fix import_tools test
  put start monit in right place during deploy
  don't bring down the sidekiq webadmin with turnout
  fixes in import_tools
  remove custom whenever command during deploy
  Update binstubs for rails 4
  add on roles clause to monit restart in capistrano
  add sidekiq initialiser to set custom redis url
  use REDIS_URL env variable in staging too
  remove unused/non-present variables in redis.conf
  move redis_password in all vault
  remove if's in redis.conf template and unused settings
  Remove unnecessary jinja block
  monit handles sidekiq with init.d script, not service
  Use ansible user for sidekiq scripts, rather than hard coded
  Run unicorn as the ansible user, otherwise it won't work
  Run correct unicorn command
  add monit config for sidekiq
  Remove unnecessary jinja blocks
  Monit tasks for memcached and unicorn
  ...
Merge pull request #132 from unepwcmc/404-redirect

404 page