Updated psycopg2 version to latest
Updated psycopg2 version to latest

Updated psycopg2 version to latest as the previous one did not work on Heroku.
shirlei/helios-server,shirlei/helios-server,shirlei/helios-server,benadida/helios-server,benadida/helios-server,benadida/helios-server,shirlei/helios-server,shirlei/helios-server,benadida/helios-server,benadida/helios-server