fix use of deprecated methods after version update

cli/cmd/prompt.go

@@ -41,6 +41,7 @@ import (
 	"github.com/google/uuid"
 	"github.com/openconfig/goyang/pkg/yang"
 	"github.com/pterm/pterm"
+	"github.com/pterm/pterm/putils"
 	"github.com/spf13/cobra"
 	"github.com/spf13/pflag"
 	"github.com/spf13/viper"
@@ -65,9 +66,9 @@ func NewPromptCompleter() *PromptCompleter {
 // Run starts the interactive completion.
 func (pc *PromptCompleter) Run() {
 	title, _ := pterm.DefaultBigText.WithLetters(
-		pterm.NewLettersFromString("go"),
-		pterm.NewLettersFromStringWithStyle("SDN", pterm.NewStyle(pterm.FgCyan)),
-		pterm.NewLettersFromString("c"),
+		putils.LettersFromString("go"),
+		putils.LettersFromStringWithStyle("SDN", pterm.NewStyle(pterm.FgCyan)),
+		putils.LettersFromString("c"),
 	).Srender()
 	description := pterm.DefaultBasicText.Sprint("Control your goSDN controller like you've never done it before!")
 	pterm.DefaultCenter.Println(title)