Heroku Postgres Database Support

[forgingdestiny]

Update psycopg2 to support new versions in heroku.

When installing via the heroku button...

Downloading https://files.pythonhosted.org/packages/7b/a8/dc2d50a6f37c157459cd18bab381c8e6134b9381b50fbe969997b2ae7dbc/psycopg2-2.6.2.tar.gz (376kB)
           Complete output from command python setup.py egg_info:
           running egg_info
           creating pip-egg-info/psycopg2.egg-info
           writing pip-egg-info/psycopg2.egg-info/PKG-INFO
           writing dependency_links to pip-egg-info/psycopg2.egg-info/dependency_links.txt
           writing top-level names to pip-egg-info/psycopg2.egg-info/top_level.txt
           writing manifest file 'pip-egg-info/psycopg2.egg-info/SOURCES.txt'
           Error: could not determine PostgreSQL version from '10.5'
           
           ----------------------------------------
       Command "python setup.py egg_info" failed with error code 1 in /tmp/pip-build-jj6r5g8c/psycopg2/
 !     Push rejected, failed to compile Python app.
 !     Push failed

[ziwon]

Resolved at #6 and also updated psycopg2 to 2.8.2 and tested PostgreSQL 11.3, thanks.