title: getting error when I try to use Drivers in CodeIgniter
body: <p>I'm trying to create a custom driver in codeigniter, but i got error.</p>
  <p>here is the File hierarchy:</p>
  <pre><code> /libraries
      /libraries/Taker
          /libraries/Taker/Taker.php
          /libraries/Taker/drivers
              /libraries/Taker/drivers/Taker_test.php
  </code></pre>
  <p>Code in libraries/Taker/Taker.php:</p>
  <pre><code>   class Taker extends CI_Driver_Library  {
          function hello() {
              echo 123;
          }
      }
  </code></pre>
  <p>Code in libraries/Taker/drivers/Taker_test.php:</p>
  <pre><code>class Taker_test extends CI_Driver {
      function world() {
          echo 123;
      }
  }
  </code></pre>
  <p>The code in the controller:</p>
  <pre><code>$this-&gt;load-&gt;driver('taker');
  $this-&gt;taker-&gt;hello(); //work
  $this-&gt;taker-&gt;test-&gt;world(); //eror here
  </code></pre>
  <p>the error i got in the controller:</p>
  <pre><code>Invalid driver requested: Taker_test
  </code></pre>
  <p>Any Suggestions?
  Thanks</p>