Update psycopg2 to 2.8.3

[pyup-bot]

This PR updates psycopg2 from 2.8.2 to 2.8.3.

Changelog

2.8.3

^^^^^^^^^^^^^^^^^^^^^^^^^^^

- Added *interval_status* parameter to
`~psycopg2.extras.ReplicationCursor.start_replication()` method and other
facilities to send automatic replication keepalives at periodic intervals
(:ticket:`913`).
- Fixed namedtuples caching introduced in 2.8 (:ticket:`928`).

Links

• PyPI: https://pypi.org/project/psycopg2
• Changelog: https://pyup.io/changelogs/psycopg2/
• Homepage: http://initd.org/psycopg/