Remove MariaDB support (#3381)

src/tests/api/test_items.py

@@ -835,7 +835,7 @@ def test_item_create_with_addon(token_client, organizer, event, item, category,
     assert resp.status_code == 400
     assert resp.content.decode() in [
         '{"addons":["The minimum count needs to be equal to or greater than zero."]}',
-        '{"addons":[{"min_count":["Ensure this value is greater than or equal to 0."]}]}',  # mysql
+        '{"addons":[{"min_count":["Ensure this value is greater than or equal to 0."]}]}',
     ]
     with scopes_disabled():
         assert 2 == Item.objects.all().count()

src/tests/travis_mysql.cfg

@@ -1,7 +0,0 @@
-[database]
-backend=mysql
-name=pretix
-user=root
-password=
-host=127.0.0.1
-port=3306