Containerd client integration

This commit:
1) Replaces the usage of containerd GRPC APIs with the containerd client for all operations related to containerd.
2) Updated containerd to v1.0alpha4+
3) Updated runc to v1.0.0

Signed-off-by: Abhinandan Prativadi <abhi@docker.com>

pkg/store/container/container.go

@@ -19,6 +19,8 @@ package container
 import (
 	"sync"
 
+	"github.com/containerd/containerd"
+
 	"github.com/kubernetes-incubator/cri-containerd/pkg/store"
 )
 
@@ -29,20 +31,35 @@ type Container struct {
 	Metadata
 	// Status stores the status of the container.
 	Status StatusStorage
-	// TODO(random-liu): Add containerd container client.
-	// TODO(random-liu): Add stop channel to get rid of stop poll waiting.
+	// Containerd container
+	Container containerd.Container
+}
+
+// Opts sets specific information to newly created Container.
+type Opts func(*Container)
+
+// WithContainer adds the containerd Container to the internal data store.
+func WithContainer(cntr containerd.Container) Opts {
+	return func(c *Container) {
+		c.Container = cntr
+	}
 }
 
 // NewContainer creates an internally used container type.
-func NewContainer(metadata Metadata, status Status) (Container, error) {
+func NewContainer(metadata Metadata, status Status, opts ...Opts) (Container, error) {
 	s, err := StoreStatus(metadata.ID, status)
 	if err != nil {
 		return Container{}, err
 	}
-	return Container{
+	c := Container{
 		Metadata: metadata,
 		Status:   s,
-	}, nil
+	}
+
+	for _, o := range opts {
+		o(&c)
+	}
+	return c, nil
 }
 
 // Delete deletes checkpoint for the container.