title: query where regexp in laravel eloquent
body: <p>I'm using laravel 5
  And I want to run this query</p>
  
  <pre><code>SELECT *
                  FROM `discussions`
                  WHERE
                    `title` REGEXP CONCAT('[[:&lt;:]]', REPLACE('".$term."', ' ', '[[:&gt;:]].*[[:&lt;:]]'), '[[:&gt;:]]')
  </code></pre>
  
  <p>I tried this</p>
  
  <pre><code>Discussion::where('title', 'REGEXP', "CONCAT('[[:&lt;:]]', REPLACE('".$term."', ' ', '[[:&gt;:]].*[[:&lt;:]]'), '[[:&gt;:]]')")-&gt;get();
  </code></pre>
  
  <p>But I did not get back anything (not even an error)
  Can this be done?</p>