python3 builds: hic2cool-0.8.0 downgrades too many common pkgs

[thomas]

look at this:

<requirements.txt>
h5py==2.8.0
pandas==0.24.2
numpy==1.16.3
scipy==1.2.1
cooler==0.8.5

So either it works w/o downgrading most of the important packages, or its time to say good bye to some tools. (Read "My way, or the highway." :)

[donald]

Default policy should be to remove the pip package which blocks us from progress. If somebody needs it, the previous python build can be used.