Project: mesos
Issue MESOS-4942: Docker runtime isolator tests may cause disk issue.
Currently slave working directory is used as docker store dir and archive dir, which is problematic. Because slave work dir is exactly `environment->mkdtemp()`, it will get cleaned up until the end of the whole test. But the runtime isolator local puller tests cp the host's rootfs, which size is relatively big. Cleanup has to be done by each test tear down.
Story points: 2