title: undefined method `symbolize_keys' after requiring active support.
body: <p>I am trying to symbolize the keys of a hash in a non rails project. I can see the symbolize_keys method is part of Active Support so I imported the library but it still doesn't work.</p>
  
  <p>Here is an example of it failing</p>
  
  <pre><code>2.4.2 :001 &gt; require 'active_support'
   =&gt; true 
  2.4.2 :002 &gt; {'test' =&gt; 'test'}.symbolize_keys
  NoMethodError: undefined method `symbolize_keys' for {"test"=&gt;"test"}:Hash
  </code></pre>
  
  <p>Expected output</p>
  
  <pre><code>{test: "test"}
  </code></pre>