Renamed main.yml and updated README

roles/mariadb/files/mysql.service

@@ -8,9 +8,9 @@ TimeoutStartSec=0
 Restart=always
 ExecStartPre=-/usr/bin/docker stop %n
 ExecStartPre=-/usr/bin/docker rm %n
-ExecStartPre=/usr/bin/docker pull mariadb:10.1.22
+ExecStartPre=/usr/bin/docker pull mariadb:10.2
 ExecStart=/usr/bin/docker run  -p 3306:3306 --name %n -v /srv/lib/mysql:/var/lib/mysql \
- -e MYSQL_ROOT_PASSWORD=geheim mariadb:10.1.22
+ -e MYSQL_ROOT_PASSWORD=geheim mariadb:10.2
  
 [Install]
 WantedBy=multi-user.target