function _clearGeneratorConfig(app, generator) {
  if (generator === '*') {
    globalConfig.removeAll();
  } else {
    globalConfig.remove(generator);
  }

  console.log('Global config has been successfully cleared');
  app.navigate('home');
}
Clear the given generator from the global config file
@param  {Object} app
@param  {String} generator Name of the generator to be clear. Use '*' to clear all generators.