Adding show/hide column options for the route:list command

Please use this formatting:

```php
		if ($this->option('show'))
		{
			$columns = explode(',', $this->option('show'));
		}
		elseif ($this->option('hide'))
		{
			$headers = array_except($this->headers, explode(',', $this->option('hide')));
			$columns = array_keys($headers);
		}
		else
		{
			$columns = array_keys($this->headers);
		}
```