The manager only requires the CLI's configuration; define a shallow interface
for this so that we don't have to import cli/command.
In addition to the CLI's configuration, `runHooks` also used the CLI's configured
StdErr output. We set the Cobra input and output streams to be the same as the
DockerCLI outputs in [newDockerCommand] and [newPluginCommand], so we can
get this from the Cobra command.
[newDockerCommand]: ea1f10b440/cmd/docker/docker.go (L148-L150)
[newPluginCommand]: ea1f10b440/cli-plugins/plugin/plugin.go (L166-L168)
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
8dcde50b6e