Allow new meta attribute 'using' for multiple database scenarios

[atkawa7]

Django pgviews current fails to work with multiple databases. The issue is the connection get called with the default database but not the alternative one. To fix that I added a meta attribute 'using' then check that in the view sync runbacklog function
https://github.com/atkawa7/django-pgviews/commit/f73ca72cfa4ff3d3a038f5cbff28cce75478bd47
https://github.com/atkawa7/django-pgviews/commit/b6b45b65202ad0f7feeb02edf72f5e388ae8fa46

[mikicz]

My fork now this supports this as of version 0.8.0. See https://github.com/mikicz/django-pgviews and https://pypi.org/project/django-pgviews-redux/.