Example does not run with import error from pulp

[rpgoldman]

When I try to run the test case per the documentation

pydcop solve --algo dpop graph_coloring.yaml

I get this error:

Traceback (most recent call last):
  File "/Users/rpg/.virtualenvs/pydcop/bin/dcop.py", line 54, in <module>
    from pydcop.commands import generate
  File "/Users/rpg/.virtualenvs/pydcop/lib/python3.9/site-packages/pydcop/commands/generate.py", line 94, in <module>
    from pydcop.commands.generators.iot import generate_iot
  File "/Users/rpg/.virtualenvs/pydcop/lib/python3.9/site-packages/pydcop/commands/generators/iot.py", line 49, in <module>
    from pulp.solvers import GLPK_CMD
ModuleNotFoundError: No module named 'pulp.solvers'

I looked and indeed there is no solvers module in pulp.

I don't know for sure, but if I had to guess, I would say that probably the pulp library has changed in some way that is not backwards-compatible, and when I looked at the setup file I see there are no version qualifiers on the pulp dependency.

With no version qualifiers, I get pulp version 2.6.0 from pypi.

Looking further, I see that pulp replaced its solvers module with apis in this commit on 5 April 2020.

Looks like rolling back to pulp 2.0 solves that problem, but then it looks like there's version skew with yaml, as well.

If you still have a working copy of pyDcop, it would be great if you would check the versions of all its dependencies and revise setup.py with those versions until you can bring this library up-to-date with the state of pypi. Thanks!