Update setup.py to work with conda.

[gideonite]

Fixes this error when running pip install .

    ERROR: Command errored out with exit status 1:
     command: /cluster/home/dgideon/software/anaconda3/envs/dim/bin/python -c 'import sys, setuptools, tokenize; sys.argv[0] = '"'"'/tmp/pip-req-build-i502lsuj/setup.py'"'"'; __file__='"'"'/tmp/pip-req-build-i502lsuj/setup.py'"'"';f=getattr(tokenize, '"'"'open'"'"', open)(__file__);code=f.read().replace('"'"'\r\n'"'"', '"'"'\n'"'"');f.close();exec(compile(code, __file__, '"'"'exec'"'"'))' egg_info --egg-base /tmp/pip-req-build-i502lsuj/pip-egg-info
         cwd: /tmp/pip-req-build-i502lsuj/
    Complete output (24 lines):
    Traceback (most recent call last):
      File "/cluster/home/dgideon/software/anaconda3/envs/dim/lib/python3.7/site-packages/setuptools/dist.py", line 221, in assert_string_list
        assert isinstance(value, (list, tuple))
    AssertionError

[MasterJEET]

I wonder if the project is still active.