Support MariaDB (#61)

Author: nakamura-to

codegen/src/main/java/org/seasar/doma/gradle/codegen/util/JdbcUtil.java

@@ -86,6 +86,7 @@ public static String inferDialectName(String url) {
             case "sqlite":
               return "sqlite";
             case "mysql":
+            case "mariadb":
               return "mysql";
             case "postgresql":
               return "postgres";