Split deploy steps in separate playbooks: part1 (#3451)

* Fix bootstrap_os/ubuntu idempotency

* Update bastion role

* move container_engine in sub-roles

* requires ansible 2.5

* ubuntu18 as first CI job

roles/container-engine/meta/main.yml

@@ -0,0 +1,23 @@
+---
+dependencies:
+  - role: container-engine/cri-o
+    when:
+      - container_manager == 'crio'
+    tags:
+      - container-engine
+      - crio
+
+  - role: container-engine/rkt
+    when:
+      - container_manager == 'rkt'
+    tags:
+      - container-engine
+      - rkt
+
+  - role: container-engine/docker
+    when:
+      - container_manager == 'docker' or container_manager == "rkt"
+    tags:
+      - container-engine
+      - docker
+      - rkt