Added support for the instance_type key in create container options

Author: turtle0x1

src/Endpoint/Containers.php

@@ -638,6 +638,7 @@ private function getOptions($name, $options)
             'ephemeral',
             'config',
             'devices',
+            'instance_type'
         ];
         $opts         = array_intersect_key($options, array_flip((array) $only));
         $opts['name'] = $name;