Mariadb upgrade

Minor versions of mariadb upgrade do not require full cluster stop.
Full cluster stop will need to be address during the move to 10.1 at
some time in the future.

Change-Id: Ia048a3fd4d79921f827f3b88c623d26db506bfc3
Partially-Implements: blueprint upgrade-kolla
Implements: blueprint upgrade-mariadb

ansible/roles/mariadb/tasks/do_upgrade.yml

+---
+- include: start.yml
+
+- include: register.yml

ansible/roles/mariadb/tasks/upgrade.yml

 ---
+- include: config.yml
+
+- include: do_upgrade.yml
+  serial: "30%"
+
+# Test haproxy user through VIP
+- include: check.yml