Integrate a docker image providing all php versions, the requiered extensions and composer

[jclaveau]

Target

• call phpunit / composer / php retrocompat choosing the php version with no php installed locally

Done

• Find docker image of sury repos

Todo

• Write a function listing available PHP versions (php, php5.6, php7.X, docker-compose)
• Setup php extensions based on composer.json
• Update the readme
• Add a --php 5.6|7.X option to ./phpunit to specify the php version

[jclaveau]

https://github.com/jtreminio/php-docker