Exclude tables with table_type of VIEW

This excludes views registered by PostGIS 2.x like geography_columns, geometry_columns, raster_columns and raster_overviews.

The table_name != 'geometry_columns' is kept for PostGIS 1.5 compatibility. The type changed to VIEW in PostGIS 2.0.

Failing tests: https://travis-ci.org/jsor/dbal/builds/40528525 (See #724)