Symlink shared/.env.production to current/.env.production

:fork_and_knife: So there aren't any conflicts between the .env file in the Supermarket repo we should symlink shared/.env.production to current/.env.production which will take precedence over .env.
Can you have two symlink_before_migrate statements here? Not sure this even works. You should be giving it a single hash anyway with `.env.production` and `unicorn.rb` as keys.