title: Factory Girl + Mongoid embedded documents in fixtures
body: <p>Let’s say you have the following mongoid documents:</p>
  
  <pre><code>class User
      include Mongoid::Document
      embeds_one :name
  end
  
  class UserName
      include Mongoid::Document
      field :first
      field :last_initial
  
      embedded_in :user
  end
  </code></pre>
  
  <p>How do you create a factory girl factory which initializes the embedded first name and last initial?  Also how would you do it with an <code>embeds_many</code> relationship?</p>