Version conflicts

[typiconman]

Running make customize leads to the following error message:

ERROR: Cannot install -r requirements.txt (line 25), -r requirements.txt (line 30), fontbakery==0.12.8 and freetype-py==2.4.0 because these package versions have conflicting dependencies.

The conflict is caused by:
    The user requested freetype-py==2.4.0
    diffenator2 0.4.3 depends on freetype-py
    fontbakery 0.12.8 depends on freetype-py<2.4.0
    The user requested freetype-py==2.4.0
    diffenator2 0.4.3 depends on freetype-py
    fontbakery 0.12.8 depends on freetype-py<2.4.0
ERROR: ResolutionImpossible: for help visit https://pip.pypa.io/en/latest/topics/dependency-resolution/#dealing-with-dependency-conflicts

To fix this you could try to:
1. loosen the range of package versions you've specified
2. remove package versions to allow pip attempt to solve the dependency conflict

Please advise.