MAGETWO-36367: Fix Messages in Setup CLI Commands

 - Wrap none with single quotes to specify as the input value.

Author: Fred Sung

setup/src/Magento/Setup/Console/Command/AbstractMaintenanceCommand.php

@@ -53,7 +53,7 @@ protected function configure()
                 self::INPUT_KEY_IP,
                 null,
                 InputOption::VALUE_IS_ARRAY | InputOption::VALUE_REQUIRED,
-                'Allowed IP addresses (use none to clear allowed IP list)'
+                "Allowed IP addresses (use 'none' to clear allowed IP list)"
             ),
         ];
         $this->setDefinition($options);