CircleCI 1.0 - Postgres service not starting - Certificate issue

Contrary to the CircleCI 1.0 documentation, which states that Postgres service is already running in the docker container mode, Postgres is down.

When I try to up the postgres service using sudo service postgresql start it fails with following:

Starting PostgreSQL 9.5 database server
 * The PostgreSQL server failed to start. Please check the log output:
2018-01-16 10:57:07.631 UTC [17225] FATAL:  could not access private key file "/etc/ssl/private/ssl-cert-snakeoil.key": Permission denied!

What is the solution for this?