cookbook helloworld requirement install failure

[jonnyhoff]

pip install -r requirements.txt 
Collecting pytz (from -r requirements.txt (line 1))
  Using cached https://files.pythonhosted.org/packages/e7/f9/f0b53f88060247251bf481fa6ea62cd0d25bf1b11a87888e53ce5b7c8ad2/pytz-2019.3-py2.py3-none-any.whl
Collecting django~=2.2 (from -r requirements.txt (line 2))
  Using cached https://files.pythonhosted.org/packages/2b/b2/eb6230a30a5cc3a71b4df733de95c1a888e098e60b5e233703936f9c4dad/Django-2.2.10-py3-none-any.whl
Collecting django-material-pro<2.0 (from -r requirements.txt (line 3))
  Could not find a version that satisfies the requirement django-material-pro<2.0 (from -r requirements.txt (line 3)) (from versions: )
No matching distribution found for django-material-pro<2.0 (from -r requirements.txt (line 3))

[kmmbvnr]

The Cookbook is really all about the Pro features, that requires to access to private Pypi server. I haven't had the chance to keep up a separate codebase for the open-source version, sorry about that.