chore(mariadb): add role metadata

roles/mariadb/meta/main.yml

@@ -0,0 +1,10 @@
+---
+allow_duplicates: true
+dependencies: []
+galaxy_info:
+  role_name: mariadb
+  description: >-2
+    Deploy mariadb using docker
+  galaxy_tags:
+    - mariadb
+    - docker