What is the problem with composer?

Question

Composer

Actually I'm trying to do the following

sudo composer require --prefer-dist yiisoft/yii2-redis

get

Your requirements could not be resolved to an installable set of packages.

  Problem 1
    - kakserpom/phpdaemon dev-master requires ext-event >=1.6.0 -> the requested PHP extension event is missing from your system.
    - nizsheanez/yii2-websocket-application v0.5 requires kakserpom/phpdaemon dev-master -> satisfiable by kakserpom/phpdaemon[dev-master].
    - Installation request for nizsheanez/yii2-websocket-application ^0.5.0 -> satisfiable by nizsheanez/yii2-websocket-application[v0.5].

  To enable extensions, verify that they are enabled in those .ini files:
    - /etc/php5/cli/php.ini
    - /etc/php5/cli/conf.d/05-opcache.ini
    - /etc/php5/cli/conf.d/10-pdo.ini
    - /etc/php5/cli/conf.d/20-curl.ini
    - /etc/php5/cli/conf.d/20-gd.ini
    - /etc/php5/cli/conf.d/20-json.ini
    - /etc/php5/cli/conf.d/20-mysql.ini
    - /etc/php5/cli/conf.d/20-mysqli.ini
    - /etc/php5/cli/conf.d/20-pdo_mysql.ini
    - /etc/php5/cli/conf.d/20-readline.ini
  You can also run `php --ini` inside terminal to see which files are used by PHP in CLI mode.

Installation failed, reverting ./composer.json to its original content.

I give php --ini I get

Configuration File (php.ini) Path: /etc/php5/cli
Loaded Configuration File:         /etc/php5/cli/php.ini
Scan for additional .ini files in: /etc/php5/cli/conf.d
Additional .ini files parsed:      /etc/php5/cli/conf.d/05-opcache.ini,
/etc/php5/cli/conf.d/10-pdo.ini,
/etc/php5/cli/conf.d/20-curl.ini,
/etc/php5/cli/conf.d/20-gd.ini,
/etc/php5/cli/conf.d/20-json.ini,
/etc/php5/cli/conf.d/20-mysql.ini,
/etc/php5/cli/conf.d/20-mysqli.ini,
/etc/php5/cli/conf.d/20-pdo_mysql.ini,
/etc/php5/cli/conf.d/20-readline.ini

the minimum stability is dev before that was stability please explain where I'm stupid