Release 1.22.1

Release 1.21.2

Update docker remote api to 1.22

Bug fixing for 1.21

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