This makes it possible to choose the graphdriver and the execdriver
which is going to be used for the cli integration tests.
Docker-DCO-1.1-Signed-off-by: Cristian Staretu <cristian.staretu@gmail.com> (github: unclejack)
Upstream-commit: 62b08f557db91cc5cd12ea9ceb0a4d8cf3d6e0f1
Component: engine