Added basic Docker abstraction, closes #16

Signed-off-by: Daniel Farrell <dfarrell@redhat.com>
Merge branch 'master' into dev
Updated docker sock perm checks to consider gid. Closes #17

Signed-off-by: Daniel Farrell <dfarrell@redhat.com>
Backed ODL start/stop method up to Docker lib, closes #18

Signed-off-by: Daniel Farrell <dfarrell@redhat.com>