2.30.6

• Improve handling mqtt connection
• Implement getUsers feature,
  for example :

QiscusApi.getInstance().getUsers(1, 20, "")
                .subscribeOn(Schedulers.io())
                .observeOn(AndroidSchedulers.mainThread())
                .subscribe(new Action1<List<QiscusAccount>>() {
                    @Override
                    public void call(List<QiscusAccount> qiscusAccounts) {
                    
                    }
                }, new Action1<Throwable>() {
                    @Override
                    public void call(Throwable throwable) {
                        throwable.printStackTrace();
                    }
                })