Include el7 mariadb support in mysql integration test

test/integration/roles/setup_mysql_db/tasks/main.yml

@@ -17,7 +17,12 @@
 # along with Ansible.  If not, see <http://www.gnu.org/licenses/>.
 
 # ============================================================
-- include_vars: '{{ ansible_os_family }}.yml' 
+- include_vars: '{{ item }}'
+  with_first_found:
+      - files:
+        - '{{ ansible_os_family }}-{{ ansible_distribution_major_version }}.yml'
+        - '{{ ansible_os_family }}.yml'
+      paths: '../vars'
 
 - name: install mysqldb_test rpm dependencies
   yum: name={{ item }} state=latest

test/integration/roles/setup_mysql_db/vars/RedHat-7.yml

+mysql_service: 'mariadb'
+
+mysql_packages:
+    - mariadb-server
+    - MySQL-python
+    - bzip2