Fixes issue #114 where batch native queries did not accept DELETE statements

Code like this fails because DELETE statement are incorrectly forbidden.

```java
        batch.batchNativeStatement(
                delete().from(NoSQLContactsInProfile.TABLE_NAME)
                        .where(eq("user_id", user.getUserId()))
                        .and(eq("profile_id", profileToDelete.getId()))
        );
```