Cannot build docker image

[devonhk]

Problem
psycopg2 fails to install

Repro steps

1. Clone repo
2. ./build.sh

Output:

Collecting psycopg2 (from -r requirements.txt (line 37))
  Downloading psycopg2-2.7.4.tar.gz (425kB)
    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: pg_config executable not found.
    
    pg_config is required to build psycopg2 from source.  Please add the directory
    containing pg_config to the $PATH or specify the full executable path with the
    option:
    
        python setup.py build_ext --pg-config /path/to/pg_config build ...
    
    or with the pg_config option in 'setup.cfg'.
    
    If you prefer to avoid building psycopg2 from source, please install the PyPI
    'psycopg2-binary' package instead.
    
    For further information please check the 'doc/src/install.rst' file (also at
    <http://initd.org/psycopg/docs/install.html>).
    
    
    ----------------------------------------
Command "python setup.py egg_info" failed with error code 1 in /tmp/pip-build-17qop12v/psycopg2/
The command '/bin/sh -c source /titan/bin/activate && pip install -r requirements.txt && pip install Flask-SQLAlchemy' returned a non-zero code: 1

Additonal notes

docker-compose up craps out in the same spot