removing dump_schema_information method

Removing dump_schema_informatio. The latest version of ActiveRecord already calls this method at a high level.  https://github.com/rails/rails/blob/35a9f7a6353ea12dd3103366e84ccc90123c3583/activerecord/lib/active_record/railties/databases.rake#L273-L288

Having this in the oracle-enhanced gem causes duplicate insert schema migrations in the structure.sql file.