title: How can I pass *.py to pycco via tox?
body: <p>The following command works:</p>
  
  <pre><code>$ pycco *.py
  # generates literate-style documentation
  # for all .py files in the current folder
  </code></pre>
  
  <p>And the following snippet in my tox.ini file works as expected:</p>
  
  <pre><code>[testenv:pycco]
  deps =
      pycco
  commands =
      pycco manage.py
  # generates literate-style documentation
  # for manage.py
  </code></pre>
  
  <p>But if I try to use a glob:</p>
  
  <pre><code>[testenv:pycco]
  deps =
      pycco
  commands =
      pycco *.py
  </code></pre>
  
  <p>...I get the following error:</p>
  
  <pre><code>  File "/home/user/Documents/project/.tox/pycco/lib/python3.7/site-packages/pycco/main.py", line 79, in generate_documentation
      code = open(source, "rb").read().decode(encoding)
  FileNotFoundError: [Errno 2] No such file or directory: '*.py'
  </code></pre>
  
  <p>How can I pass <code>*.py</code> to pycco via tox?</p>