CpuStats.CpuUsage includes TotalUsage

Docker-DCO-1.1-Signed-off-by: Bernerd Schaefer <bj.schaefer@gmail.com> (github: bernerdschaefer)
Merge pull request #34 from bernerdschaefer/cgroup-stats-total-cpu-usage

CpuStats.CpuUsage includes TotalUsage