Provide PostgreSQL and wal2json Docker image

Summary:
Sentry requires a custom version of the extension wal2json
for the Change Data Capture (CDC) toolkit.

The current supported PostgreSQL version is 9.6.

Ref T1791

Test Plan: Deploy on docker-002 for container sentry_db

Reviewers: dereckson

Reviewed By: dereckson

Maniphest Tasks: T1791

Differential Revision: https://devcentral.nasqueron.org/D2864