Improve tests: don't install daemon when running inside a container (#56)

* If running inside a container, only install docker CLI, not docker daemon.

ci_complete

* Fix OpenSUSE.

tests/integration/targets/setup_docker/tasks/RedHat-7.yml

@@ -34,7 +34,7 @@
 
 - name: Install docker
   yum:
-    name: "{{ docker_packages }}"
+    name: "{{ docker_packages if needs_docker_daemon else docker_cli_packages }}"
     state: present
   notify: cleanup docker
 
@@ -43,3 +43,4 @@
     name: docker
     state: started
   ignore_errors: "{{ ansible_virtualization_type in ['docker', 'container', 'containerd'] }}"
+  when: needs_docker_daemon