Update of dependencies

- Update PHPUnit, PHPCode_sniffer
- Remove apigen

Update phpunit configuration

Add MySQL version to the environment variables

The default version of MySQL is 5.7.22.

This change follows the change of MySQL for version 8 and the possible incompatibility with php and phpMyAdmin. see the links:

- https://bugs.php.net/bug.php?id=76243
- https://stackoverflow.com/questions/49948350/phpmyadmin-on-mysql-8-0

Documentation improvement

Update README

Add a dynamic host name in the configuration

 - Improve Makefile commands
 - Update documentation

Update README

Add Version Badge

Update README

Fix composer apigen error