It should be include_playbook

... the replacement for impotrt for static includes, that is....

site.yml

@@ -1,15 +1,15 @@
 ---
-- import_tasks: common.yml
-- import_tasks: rabbitmq.yml
-- import_tasks: memcached.yml
-- import_tasks: mariadb.yml
-- import_tasks: keystone.yml
-- import_tasks: glance-controller.yml
-- import_tasks: nova-controller.yml
-- import_tasks: neutron-controller.yml
-- import_tasks: cinder-controller.yml
-- import_tasks: cinder-storage.yml
-- import_tasks: nova-compute.yml
-- import_tasks: horizon.yml
-- import_tasks: heat.yml
-- import_tasks: post-install.yml
+- import_playbook: common.yml
+- import_playbook: rabbitmq.yml
+- import_playbook: memcached.yml
+- import_playbook: mariadb.yml
+- import_playbook: keystone.yml
+- import_playbook: glance-controller.yml
+- import_playbook: nova-controller.yml
+- import_playbook: neutron-controller.yml
+- import_playbook: cinder-controller.yml
+- import_playbook: cinder-storage.yml
+- import_playbook: nova-compute.yml
+- import_playbook: horizon.yml
+- import_playbook: heat.yml
+- import_playbook: post-install.yml