Revert "Remove etcd role"

This reverts commit 5e0036defd.

metal/roles/etcd/tasks/main.yml

@@ -0,0 +1,11 @@
+- name: Create etcd container
+  docker_container:
+    name: etcd-tfstate
+    image: bitnami/etcd
+    restart_policy: always
+    env:
+      ALLOW_NONE_AUTHENTICATION: "yes"
+    published_ports:
+      - 2379:2379
+    volumes:
+      - tfstate:/bitnami/etcd/data