Spree + Heroku + Wercker continuous deployment

wercker.yml

box: wercker/ubuntu12.04-ruby2.0.0
services:
  - wercker/postgresql
build:
  steps:
    - bundle-install
    - rails-database-yml
    - script:
        name: db:setup
        code: bundle exec rake db:setup
    - script:
        name: echo ruby information
        code: |
          echo "ruby version $(ruby --version) running"
          echo "from location $(which ruby)"
          echo -p "gem list: $(gem list)"
    - script:
        name: Enable virtual display
        code: |-
          # Start xvfb which gives the context an virtual display
          # which is required for tests that require an GUI
          export DISPLAY=:99.0
          start-stop-daemon --start --quiet --pidfile /tmp/xvfb_99.pid --make-pidfile --background --exec /usr/bin/Xvfb -- :99 -screen 0 1024x768x24 -ac +extension GLX +render -noreset

          # Give xvfb time to start. 3 seconds is the default for all xvfb-run commands.
          sleep 3
    # Install (apt-get) packages
    - install-packages:
        packages: libqtwebkit-dev
    - script:
        name: rspec
        code: bundle exec rspec
  after-steps:
    - hipchat-notify:
        token: $HIPCHAT_TOKEN
        room-id: $REDACTED  
        from-name: wercker
deploy:
  steps:
    - heroku-deploy:
        # configurable on wercker under the settings tab
        key-name: HEROKU_DEPLOY_KEY_PAIR
  after-steps:
    - hipchat-notify:
        token: $HIPCHAT_TOKEN
        room-id: $HIPCHAT_ROOM
        from-name: wercker
    - script:
        name: Update database
        code: heroku run rake db:migrate --app $HEROKU_APP_NAME
    - script:
        # puma boot times were angering heroku, this seems to help :(
        name: pause for dramatic effect
        code: sleep 5
    - script:
        name: Reset heroku app servers
        code: heroku restart --app $HEROKU_APP_NAME