title: Use mongo operator $and in Phalcon\Mvc\Collection
body: <p>im trying to use the operator $and of MongoDB applied to the Phalcon\Mvc\Collection as follow:</p>
  
  <pre><code>   $documents = Staff::find( $condition);
  </code></pre>
  
  <p>with array $<strong>condition</strong> having the "<strong>role</strong>" like this:</p>
  
  <pre><code>$condition["role"] = [
              "\$regex" =&gt; "$somevalue",  
              "\$and"=&gt; [
                  '$ne' =&gt; "admin" 
                  ]     
              ];   
  </code></pre>
  
  <p>and i get this error </p>
  
  <blockquote>
    <p>Can't canonicalize query: Bad Value: unknown operator: $and'</p>
  </blockquote>
  
  <p>Please help me solve this. <br>
  Is there any better way to apply multi conditions to this "<strong>role</strong>"?</p>