Makara on heroku

.profile

export MASTER_URL=$DATABASE_URL

database.yml

development:
  url: <%= ENV['DATABASE_URL'] %>
test:
  url: <%= ENV['TEST_DATABASE_URL'] %>
production:
  url: <%= ENV.fetch('MASTER_URL', '').sub(/^postgres/, "postgresql-makara") %>

  makara:
    connections:
      - role: master
      # MASTER_URL is set in .profile, makara doesn't like it when you use DATABASE_URL here directly
        url: <%= ENV['MASTER_URL'] %>
      <% if ENV['SLAVE_URL'].present? %>
      - role: slave
        url: <%= ENV['SLAVE_URL'] %>
      <% end %>

HI! I try to do exaclty the same thing, but it does not work for me :(
Can you tell me your ruby version please.
Thank you