title: coverage.py not reporting error from run command
body: <p>I have a bash script that runs my tests:</p>
  <pre><code>#!/bin/bash
  coverage run --source='directory_for_coverage' manage.py test
  coverage report --fail-under=87
  </code></pre>
  <p>but when I run the script it only returns an error code if the coverage fails, not if one of the tests fails. I would think that because I am not using the <code>--ignore-errors</code> switch that <code>coverage run</code> should return the error code from the failing test. What am I missing?</p>