1. It's a cgroup api, fit the general defination that we take
cgroup options as kind of resource options.
2. It's common usage and very helpful as explained here:
https://github.com/docker/docker/pull/18270#issuecomment-160561316
3. It's already in `Resource` struct in
daemon/execdriver/driver_unix.go
Signed-off-by: Qiang Huang <h.huangqiang@huawei.com>
Upstream-commit: 8498ed73f7b35da807b5d5dcf532114c7b3df52d
Component: engine