Add skeleton of new libpod API

Signed-off-by: Matthew Heon <mheon@redhat.com>

libpod/pod/pod.go

@@ -0,0 +1,36 @@
+package pod
+
+import (
+	"github.com/kubernetes-incubator/cri-o/libpod/ctr"
+)
+
+// Pod represents a group of containers that may share namespaces
+type Pod struct {
+	// TODO populate
+}
+
+// Start starts all containers within a pod that are not already running
+func (p *Pod) Start() error {
+	return ctr.ErrNotImplemented
+}
+
+// Stop stops all containers within a pod that are not already stopped
+func (p *Pod) Stop() error {
+	return ctr.ErrNotImplemented
+}
+
+// Kill sends a signal to all running containers within a pod
+func (p *Pod) Kill(signal uint) error {
+	return ctr.ErrNotImplemented
+}
+
+// GetContainers retrieves the containers in the pod
+func (p *Pod) GetContainers() ([]*ctr.Container, error) {
+	return nil, ctr.ErrNotImplemented
+}
+
+// Status gets the status of all containers in the pod
+// TODO This should return a summary of the states of all containers in the pod
+func (p *Pod) Status() error {
+	return ctr.ErrNotImplemented
+}