pg_stat_statements comes with its own view which shoulnd't be recreated

fixes the following error:
> ERROR:  cannot drop view pg_stat_statements because extension
> pg_stat_statements requires it
> HINT:  You can drop extension pg_stat_statements instead.
ignore all built-in views of postgresql
fallback for active_record 3.2
Merge pull request #147 from everplays/avoid_recreating_pg_stat_statements_view_that_comes_with_extension

pg_stat_statements comes with its own view which shoulnd't be recreated