Move memcache to 'extra'.

src/BuildSettingsCommand.php

@@ -67,12 +67,14 @@ EOT
         $stageParams = $siteParams;
         $stageParams['settings'] = $stageSettings;
         $context = [
+          'extra' => array_diff_key($params, ['instance' => 0, 'sites' => 0]),
           'instance' => $params['instance'],
           'name' => $name,
           'stage' => $stage,
           'site' => $stageParams,
         ];
         $destination = "web/sites/${context['name']}/${context['stage']}.settings.local.php";
+        echo "Building $destination\n";
         [$msg, $error] = $this->render($wrapper, $context, $destination);
         if ($error) {
           $output->writeln(sprintf("Failed rendering %s settings for site %s: %s", $stage, $name, $msg));