oci: join crio-conmon for cgroupfs

Signed-off-by: Antonio Murdaca <runcom@redhat.com>

vendor/github.com/containerd/cgroups/README.md

@@ -0,0 +1,112 @@
+# cgroups
+
+[![Build Status](https://travis-ci.org/containerd/cgroups.svg?branch=master)](https://travis-ci.org/containerd/cgroups)
+
+[![codecov](https://codecov.io/gh/containerd/cgroups/branch/master/graph/badge.svg)](https://codecov.io/gh/containerd/cgroups)
+
+Go package for creating, managing, inspecting, and destroying cgroups.
+The resources format for settings on the cgroup uses the OCI runtime-spec found
+[here](https://github.com/opencontainers/runtime-spec).
+
+## Examples
+
+### Create a new cgroup
+
+This creates a new cgroup using a static path for all subsystems under `/test`.
+
+* /sys/fs/cgroup/cpu/test
+* /sys/fs/cgroup/memory/test
+* etc....
+
+It uses a single hierarchy and specifies cpu shares as a resource constraint and
+uses the v1 implementation of cgroups.
+
+
+```go
+shares := uint64(100)
+control, err := cgroups.New(cgroups.V1, cgroups.StaticPath("/test"), &specs.LinuxResources{
+    CPU: &specs.CPU{
+        Shares: &shares,
+    },
+})
+defer control.Delete()
+```
+
+### Create with systemd slice support
+
+
+```go
+control, err := cgroups.New(cgroups.Systemd, cgroups.Slice("system.slice", "runc-test"), &specs.LinuxResources{
+    CPU: &specs.CPU{
+        Shares: &shares,
+    },
+})
+
+```
+
+### Load an existing cgroup
+
+```go
+control, err = cgroups.Load(cgroups.V1, cgroups.StaticPath("/test"))
+```
+
+### Add a process to the cgroup
+
+```go
+if err := control.Add(cgroups.Process{Pid:1234}); err != nil {
+}
+```
+
+###  Update the cgroup 
+
+To update the resources applied in the cgroup
+
+```go
+shares = uint64(200)
+if err := control.Update(&specs.LinuxResources{
+    CPU: &specs.CPU{
+        Shares: &shares,
+    },
+}); err != nil {
+}
+```
+
+### Freeze and Thaw the cgroup
+
+```go
+if err := control.Freeze(); err != nil {
+}
+if err := control.Thaw(); err != nil {
+}
+```
+
+### List all processes in the cgroup or recursively
+
+```go
+processes, err := control.Processes(cgroups.Devices, recursive)
+```
+
+### Get Stats on the cgroup
+
+```go
+stats, err := control.Stat()
+```
+
+By adding `cgroups.IgnoreNotExist` all non-existent files will be ignored, e.g. swap memory stats without swap enabled
+```go
+stats, err := control.Stat(cgroups.IgnoreNotExist)
+```
+
+### Move process across cgroups
+
+This allows you to take processes from one cgroup and move them to another.
+
+```go
+err := control.MoveTo(destination)
+```
+
+### Create subcgroup
+
+```go
+subCgroup, err := control.New("child", resources)
+```