v1.3.0

• Feature: Add support for custom filter callbacks
  (#25 by @clue)

  $tokenizer = new Tokenizer();
  $tokenizer->addFilter('ip', function ($value) {
      return filter_var($ip, FILTER_VALIDATE_IP);
  });
  $tokenizer->addFilter('lower', function (&$value) {
      $value = strtolower($value);
      return true;
  });
  
  $router = new Router($tokenizer);
  $router->add('add <name:lower>', function ($args) { });
  $router->add('--search=<address:ip>', function ($args) { });

• Improve test suite by locking Travis distro so new future defaults will not break the build
  (#24 by @clue)