Add play to everything playb. for deploying Docker Compose applications

Also introduce a new group for hosts, for which this play should be run,
called Docker_Compose_Hosts.
Finally add cit-ansible-test and cit-docker-host to this group with an
empty project list initially.

playbooks/everything.yaml

@@ -5,3 +5,8 @@
   hosts: Docker_Hosts
   roles:
     - docker
+
+- name: Ensure deployment of Docker Compose applications
+  hosts: Docker_Compose_Hosts
+  roles:
+    - docker_compose