Enable shell completion descriptions for bash

Cobra provides support for completion descriptions for bash.
It was turned off because of a bug with certain bash menu options which
have been fixed by Cobra 1.3.0.

Signed-off-by: Marc Khouzam <marc.khouzam@gmail.com>

staging/src/k8s.io/kubectl/pkg/cmd/completion/completion.go

@@ -167,7 +167,7 @@ func runCompletionBash(out io.Writer, boilerPlate string, kubectl *cobra.Command
 		return err
 	}
 
-	return kubectl.GenBashCompletionV2(out, false) // TODO: Upgrade to Cobra 1.3.0 or later before including descriptions (See https://github.com/spf13/cobra/pull/1509)
+	return kubectl.GenBashCompletionV2(out, true)
 }
 
 func runCompletionZsh(out io.Writer, boilerPlate string, kubectl *cobra.Command) error {