CLI shows env var if set in help, override

Signed-off-by: jolheiser <john.olheiser@gmail.com>

cmd/cmd.go

@@ -44,6 +44,7 @@ func New() *cli.App {
 			Name:        "token",
 			Aliases:     []string{"t"},
 			Usage:       "gpm auth token to use",
+			DefaultText: "${GPM_TOKEN}",
 			EnvVars:     []string{"GPM_TOKEN"},
 			Destination: &flags.Token,
 		},