title: Pipenv with coverage ignores kill
body: <p>In a bash script I run coverage in a chalice project through pipenv. But the <code>.coverage</code> file is not created. The file is normally created after a gracefull end of the process. But <code>ps aux</code> shows, that the process lives after the script ends. When running the first line in the terminal and aborting with <code>Ctrl+C</code> everything works fine</p>
  <pre class="lang-sh prettyprint-override"><code>python3 -m pipenv run coverage run --source=chalicelib $(pipenv --venv)/bin/chalice local --stage test --no-autoreload --port 8003 &gt;chalice.log 2&gt;&amp;1 &amp;
  echo &quot;$!&quot; &gt; chalice.pid
  # here some e2e tests run
  kill -INT $(&lt; chalice.pid)
  </code></pre>