feat: template docker compose file

roles/ynh_apps/templates/compose.yml.j2

+version: "{{ docker_compose_version }}"
+services:
+{% for app in docker_compose_apps %}
+  {{ app.name }}:
+    image: "{{ app.image }}"
+{% if app.ports %}
+    ports:
+{% for port in app.ports %}
+      - "{{ port }}"
+{% endfor %}
+{% endif %}
+{% if app.volumes %}
+    volumes:
+{% for volume in app.volumes %}
+      - {{ volume }}
+{% endfor %}
+{% endif %}
+{% if app.environment %}
+    environment:
+{% for var in app.environment %}
+      - {{ var }}
+{% endfor %}
+{% endif %}
+{% endfor %}