title: How to uniq an array case insensitive
body: <p>As far as i know, the result of</p>
  
  <pre><code>["a", "A"].uniq 
  </code></pre>
  
  <p>is </p>
  
  <pre><code>["a", "A"]
  </code></pre>
  
  <p>My question is:</p>
  
  <p>How do I make ["a", "A"].uniq give me either ["a"] or ["A"]</p>