Change deprecated module name for postgresql
Change deprecated module name for postgresql

Change module name from postgres to postgresql since it was
deprecated a long time ago.

See commit: https://github.com/zzzeek/sqlalchemy/commit/c59bf0007f0148b73c80a3d6b86d6c66ae0ab422

Change-Id: Ia2619d4b5608c181eb5759dbd346116a128055d3

stackforge/monasca-api,stackforge/monasca-api,stackforge/monasca-api,openstack/monasca-api,openstack/monasca-api,openstack/monasca-api,stackforge/monasca-api