Fix the help flag

With the forked version of kingpin, there was a side effect with the --help flag. Previously, the help flag was not considered as managed and it was not handled by kingpin. This was the desired behavior since we do not want to interfere with the sub command executed by terraform which most likely will have a --help.

cli.go

@@ -104,10 +104,13 @@ type TGFApplication struct {
 func NewTGFApplication(args []string) *TGFApplication {
 	d := formatDescription()
 	base := kingpin.New("tgf", d).Author("Coveo").AllowUnmanaged().AutoShortcut().InitOnlyOnce().DefaultEnvars().UsageWriter(color.Output)
+	base.DeleteFlag("help")
+	base.DeleteFlag("help-long")
 	app := TGFApplication{Application: base}
 	swFlagON := func(name, description string) *kingpin.FlagClause {
 		return app.Flag(name, fmt.Sprintf("ON by default: %s, use --no-%s to disable", description, name)).Default(true)
 	}
+	app.Flag("help-tgf", "Show context-sensitive help (also try --help-man)").Short('H').Action(app.ShowHelp).Bool()
 	app.Flag("image", "Use the specified image instead of the default one").PlaceHolder("coveo/tgf").NoAutoShortcut().StringVar(&app.Image)
 	app.Flag("image-version", "Use a different version of docker image instead of the default one").PlaceHolder("version").Default("-").StringVar(&app.ImageVersion)
 	app.Flag("tag", "Use a different tag of docker image instead of the default one").Short('T').NoAutoShortcut().PlaceHolder("latest").Default("-").StringVar(&app.ImageTag)
@@ -136,9 +139,8 @@ func NewTGFApplication(args []string) *TGFApplication {
 	app.Flag("config-files", "Set the files to look for (default: "+remoteDefaultConfigPath+")").PlaceHolder("<files>").StringVar(&app.ConfigFiles)
 	app.Flag("config-location", "Set the configuration location").PlaceHolder("<path>").StringVar(&app.ConfigLocation)
 
-	app.HelpFlag.Help("Show context-sensitive help (also try --help-man).").Short('H').NoAutoShortcut()
 	kingpin.CommandLine = app.Application
-	app.UsageTemplate(strings.Replace(kingpin.DefaultUsageTemplate, "{{.Help|Wrap 0}}", "{{.Help}}", -1))
+	kingpin.HelpFlag = app.GetFlag("help-tgf")
 
 	app.Parse(args)
 	return &app
@@ -189,6 +191,17 @@ func (app *TGFApplication) Debug(format string, args ...interface{}) {
 	}
 }
 
+// ShowHelp simply display the help context and quit execution
+func (app *TGFApplication) ShowHelp(c *kingpin.ParseContext) error {
+	app.Writer(os.Stdout)
+	usage := strings.Replace(kingpin.DefaultUsageTemplate, "{{.Help|Wrap 0}}", "{{.Help}}", -1)
+	if err := app.UsageForContextWithTemplate(c, 2, usage); err != nil {
+		return err
+	}
+	os.Exit(0)
+	return nil
+}
+
 // Run execute the application
 func (app *TGFApplication) Run() int {
 	if app.GetCurrentVersion {