title: Laravel validation by extension
body: <p>need help to validate my form input
  i need user only able to upload file with extension .log</p>
  
  <p>so far i've tried as the code shown below but the validator still reject the input even the file is .log</p>
  
  <p>thanks in advance</p>
  
  <pre><code>$validator = Validator::make($request-&gt;all(),
              [
                  'email' =&gt; 'required|email',
                  'file_log' =&gt; 'mimes:text/plain,log'
              ],
              [
                  'email.email' =&gt; 'Please input valid email address',
                  'file_log.mimes' =&gt; 'Mohon hanya mengunggah file yang berekstensi .log ',
              ]
          );
  </code></pre>