run method
Runs this command.
The return value is wrapped in a Future if necessary and returned by
CommandRunner.runCommand.
Implementation
@override
void run() {
  if (which('flutter').found) {
    print('${green('[✓]')} Flutter installed');
    FlutterHelper.run('--version');
  } else {
    printerr('${red('[x]')} Flutter not installed');
    printerr(
      'You can install flutter in https://docs.flutter.dev/get-started/install',
    );
  }
  if (which('melos').found) {
    print('${green('[✓]')} Melos installed');
    'melos --version'.run;
  } else {
    printerr('${red('[x]')} Melos not installed');
    printerr(
      'You can install in https://docs.flutter.dev/get-started/install',
    );
  }
}