public function update($options = ['since' => InputOption::VALUE_REQUIRED]) {
    $this->rsyncTemplate();

    $starting_version = $options['since'] ?: $this->currentSchemaVersion;
    if ($this->executeSchemaUpdates($starting_version)) {
      $this->updateSchemaVersionFile();
    }
    $this->cleanup();
    $this->invokeCommand('blt:init:shell-alias');
  }