Move most test_dockercli module functions to methods of the TestDockerCli class.
Move most test_dockercli module functions to methods of the TestDockerCli class.

crcresearch/smartcontainers,crcresearch/smartcontainers,crcresearch/smartcontainers,charlesvardeman/smartcontainers,Omegaice/smartcontainers,Omegaice/smartcontainers,Omegaice/smartcontainers