tests: remove atomic and debian tasks

We don't need the atomic fact and the debian related tasks because we
only test the containers on CentOS systems.

Signed-off-by: Dimitri Savineau <dsavinea@redhat.com>
(cherry picked from commit db27a25)

tests/setup.yml

@@ -4,30 +4,12 @@
   gather_facts: true
   become: yes
   tasks :
-    - name: check if it is Atomic host
-      stat: path=/run/ostree-booted
-      register: stat_ostree
-      check_mode: no
-
-    - name: set fact for using Atomic host
-      set_fact:
-        is_atomic: '{{ stat_ostree.stat.exists }}'
-
     - name: install docker on redhat systems
       package:
         name: docker
         state: present
       when:
         - ansible_os_family == 'RedHat'
-        - not is_atomic
-
-    - name: install docker.io on debian systems
-      package:
-        name: docker.io
-        state: present
-      when:
-        - ansible_os_family == 'Debian'
-        - not is_atomic
 
     - name: allow nodes to use an insecure registry - docker
       copy: