Implement docker stats with standalone client lib.
Implement docker stats with standalone client lib.

Signed-off-by: David Calavera <b9b0c8e7f90ecf337f6797c4d2e0f1dd0dbc0324@gmail.com>

vdemeester/engine-api,thaJeztah/engine-api,mikedougherty/engine-api,rhatdan/engine-api,msabansal/engine-api,docker/engine-api,jwhonce/engine-api