title: pg_config executable not found on Windows 7 with PostgreSQL installed
body: <p>I'm following the Heroku guide on using Python with Heroku.</p>
  
  <p>I'm on the step for <a href="https://devcenter.heroku.com/articles/getting-started-with-python#declare-app-dependencies" rel="nofollow">installing dependencies</a>, but when I run <code>pip install -r requirements.txt --allow-all-external</code>, I get this error:</p>
  
  <pre><code>Error: pg_config executable not found.
  
  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'.
  </code></pre>
  
  <p>When I run <code>python setup.py build_ext --pg-config C:\Program Files\PostgreSQL\9.4\bin\pg_config.exe</code> from the Django app's root directory via Git, I get a <code>no such directory</code> error.</p>
  
  <p>What am I doing wrong?</p>