title: Command to clear log files in symfony 2
body: <p>I was wondering if there is a command to clear the log files in Symfony 2 ?
  While there is the <code>php app/console cache:clear</code> to clear the cache, I don't know any command to clear the log files (logs/dev.log and logs/prod.log).
  I have always cleared these logs manually.
  Thank you</p>