protected function setSimpleSamlPhpInstalled() {
    $project_yml = $this->getConfigValue('blt.config-files.project');

    $this->say("Updating ${project_yml}...");

    $project_config = YamlMunge::parseFile($project_yml);
    $project_config['simplesamlphp'] = TRUE;

    try {
      YamlMunge::writeFile($project_yml, $project_config);
    }
    catch (\Exception $e) {
      throw new BltException("Unable to update $project_yml.");
    }
  }