Move NewClient and AppContext to commands pkg

Signed-off-by: Michael Crosby <crosbymichael@gmail.com>

cmd/ctr/ps.go

@@ -5,6 +5,7 @@ import (
 	"os"
 	"text/tabwriter"
 
+	"github.com/containerd/containerd/cmd/ctr/commands"
 	"github.com/containerd/containerd/windows/hcsshimtypes"
 	"github.com/pkg/errors"
 	"github.com/urfave/cli"
@@ -19,7 +20,7 @@ var taskPsCommand = cli.Command{
 		if id == "" {
 			return errors.New("container id must be provided")
 		}
-		client, ctx, cancel, err := newClient(context)
+		client, ctx, cancel, err := commands.NewClient(context)
 		if err != nil {
 			return err
 		}