title: Validation for combination of two fields in laravel 5
body: <p>Can we validate combination of two fields I don't want same entry in my events table
  For example</p>
  
  <pre><code>no | event     | category
  ----------------------
  1  | Wedding   | Band
  2  | Wedding   | Food
  3  | Wedding   | Decor
  4  | Wedding   | Band  // laravel validation to avoid this
  </code></pre>
  
  <p>Like unique event</p>
  
  <pre><code>'event' =&gt; 'required|unique:events'
  </code></pre>
  
  <p>Anything like this</p>
  
  <pre><code>'event' =&gt; 'required|unique:events|category:unique'
  </code></pre>