Allow downloading of databases larger than available memory.
0.6
The pgbackups addon has been deprecated in favour of the pg:backups commands. By default, paragres now uses pg:backups, though you can specify --use-pgbackups if you need to use the pgbackups addon.
0.5
Added support for Python 3
0.4
Added support for capturing a Heroku backup. Improved readme and command line help. Made it clear that postgres database does not have to be on localhost. Added flake8 and unit tests.