Backwards incompatability of pycddlib>3.0

[MoritzHein]

When running pypoman.compute_polytope_vertices, there is an error, that cdd.Matrix__init__() does not take that many input arguments.

I think, it has to do with pycddlib changing some things in their 3.0 release.
At least the problem was fixed, when i installed pycddlib 2.1.7 prior to installing pypoman.

[stephane-caron]

Thank you for taking the time to report this issue 👍 As an immediate workaround, I have updated dependencies to pycddlib<3 so that new users don't run into the issue. You can leave this issue open until a future PR updates to the pycddlib 3 API.