title: How to generate migration with uuid primary key
body: <p>How can a model be generated from the <code>rails generate</code> command, specifying <code>uuid</code> as the column type for the primary key? </p>
  
  <p>My goal is to issue some command like the following: </p>
  
  <pre><code>rails g model widget id{uuid}
  </code></pre>
  
  <p>To generate a migration like</p>
  
  <pre><code>create_table :widgets, id: :uuid do |t|
    t.timestamps null: false
  end
  </code></pre>
  
  <p>I realize I can add <code>id: :uuid</code> after the migration is generated, but I feel like there must be some lazy way to do this. </p>