bug: deploy to heroku fails on requirements.txt

[denzuko]

• Expected Results:
  Application deploys and is accessible

• Actual Results:
  App creation failed. Please ensure you have valid values in the above form fields.

• Additional Details:
  Related to Install 2.6.1 failed psycopg/psycopg2#594
  Logs

       Collecting psycopg2==2.6.2 (from odooku-odoo-base==10.0.0->odooku-odoo-addons<11.0.0,>=10.0.0->-r /tmp/build_5de97865562797aeeed20f6dde1af6d4/requirements.txt (line 1))
         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 top-level names to pip-egg-info/psycopg2.egg-info/top_level.txt
           writing dependency_links to pip-egg-info/psycopg2.egg-info/dependency_links.txt
           writing manifest file 'pip-egg-info/psycopg2.egg-info/SOURCES.txt'
           warning: manifest_maker: standard file '-c' not found
           
           Error: could not determine PostgreSQL version from '11.6'
           
           ----------------------------------------
       Command "python setup.py egg_info" failed with error code 1 in /tmp/pip-build-PlUxPO/psycopg2/
 !     Push rejected, failed to compile Odooku app.
 !     Push failed