title: Laravel Eloquent date_format Validation fails on given format
body: <p>I want to create validation rule to validate incoming date.
  Format I want to validate is Y-m-d H:i:s. Here's my body request which I am validating:</p>
  
  <pre><code>{ "date":"2015.10.5 10:30:10" }
  </code></pre>
  
  <p>And here's my validation rule:</p>
  
  <pre><code>'date' =&gt; 'required|date_format:"Y.m.d H:i:s"',
  </code></pre>
  
  <p>And it returns: </p>
  
  <blockquote>
    <p>{"date":["The date does not match the format Y.m.d H:i:s."]}</p>
  </blockquote>