Add support for kubernetes in docker cli

- Add support for kubernetes for docker stack command
- Update to go 1.9
- Add kubernetes to vendors
- Print orchestrator in docker version command

Signed-off-by: Vincent Demeester <vincent@sbr.pm>
Signed-off-by: Silvin Lubecki <silvin.lubecki@docker.com>

cli/command/stack/kubernetes/remove.go

@@ -0,0 +1,46 @@
+package kubernetes
+
+import (
+	"fmt"
+
+	"github.com/docker/cli/cli"
+	"github.com/docker/cli/cli/command"
+	"github.com/spf13/cobra"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+)
+
+type removeOptions struct {
+	stacks []string
+}
+
+func newRemoveCommand(dockerCli command.Cli, kubeCli *kubeCli) *cobra.Command {
+	var opts removeOptions
+
+	cmd := &cobra.Command{
+		Use:     "rm STACK [STACK...]",
+		Aliases: []string{"remove", "down"},
+		Short:   "Remove one or more stacks",
+		Args:    cli.RequiresMinArgs(1),
+		RunE: func(cmd *cobra.Command, args []string) error {
+			opts.stacks = args
+			return runRemove(dockerCli, kubeCli, opts)
+		},
+	}
+	return cmd
+}
+
+func runRemove(dockerCli command.Cli, kubeCli *kubeCli, opts removeOptions) error {
+	stacks, err := kubeCli.Stacks()
+	if err != nil {
+		return err
+	}
+	for _, stack := range opts.stacks {
+		fmt.Fprintf(dockerCli.Out(), "Removing stack: %s\n", stack)
+		err := stacks.Delete(stack, &metav1.DeleteOptions{})
+		if err != nil {
+			fmt.Fprintf(dockerCli.Out(), "Failed to remove stack %s: %s\n", stack, err)
+			return err
+		}
+	}
+	return nil
+}