move mongo tasks into mongo role

ansible/roles/mongo/tasks/main.yml

@@ -0,0 +1,12 @@
+---
+- name: Start db-mongo docker container
+  become: yes
+  docker_container:
+    name: db-mongo
+    image: mongo:3.6
+    state: started
+    ports:
+      - 27017:27017
+    restart_policy: unless-stopped
+    volumes:
+      - /srv/newsblur/docker/volumes/db_mongo:/data/db

ansible/setup_mongo.yml

@@ -12,15 +12,4 @@
       - base
       - docker
       - repo
-  tasks:
-    - name: Start db-mongo docker container
-      become: yes
-      docker_container:
-        name: db-mongo
-        image: mongo:3.6
-        state: started
-        ports:
-          - 27017:27017
-        restart_policy: unless-stopped
-        volumes:
-          - /srv/newsblur/docker/volumes/db_mongo:/data/db
+      - mongo