title: Ghostscript not detected when using camelot with Pipenv
body: <p>I'm trying to use <a href="https://camelot-py.readthedocs.io/en/master/" rel="nofollow noreferrer">camelot</a> to read tables from a pdf, but when I execute <code>tables = camelot.read_pdf('foo.pdf')</code>
  I get the following error:</p>
  <p><em><strong>RuntimeError: Please make sure that Ghostscript is installed</strong></em></p>
  <p>I have installed <strong>ghostcript</strong> and <strong>python-ghostscript</strong> and some previuos versions. I have also try with <code>pipenv install &quot;camelot-py[base]&quot;</code> and <code>camelot-py</code>, but I still get the same error.</p>