Use fork name plesk/docker-php

First stable of docker PHP, on 1.21 remote api

BC break release, 100% support of all api calls

Last 0.4 release before BC break

Merge pull request docker-php#127 from tasuk/add-container-exec-inspect

Add exec inspect

Merge pull request docker-php#121 from sroze/feature/image-push

Allow to push image

Fix remote api version testing in README

Merge pull request docker-php#87 from hacfi/docs1

Docs: Improve installation, add image pull, small changes

Add interact call, refactoring callback to use \php_user_filter

Bump 0.2.3, add tls support