tests: change centos/atomic-host box name to rhel7

We'd like to test everything rhcs on the same rhel7 box.

Signed-off-by: Andrew Schoen <aschoen@redhat.com>

tests/functional/rhcs_setup.yml

@@ -20,6 +20,13 @@
         dest: "{{ change_dir }}/vagrant_variables.yml"
       when: change_dir is defined
 
+    - name: change centos/atomic-host vagrant box name to rhel7
+      replace:
+        regexp: "centos/atomic-host"
+        replace: "rhel7"
+        dest: "{{ change_dir }}/vagrant_variables.yml"
+      when: change_dir is defined
+
 - hosts: all
   gather_facts: true
   become: yes