Docker no longer has an `ExecutionDriver` as of Docker 1.11.
The field in the `docker info` API will not be present in 1.13.
Found this while working on docker/docker#25721
Signed-off-by: Brian Goff <cpuguy83@gmail.com>
Ensure setup_module is called at session level, making the test
suite not order dependent. Test files can be invoked independently.
Signed-off-by: Joffrey F <joffrey@docker.com>