Follow up PR - Githubissues

Follow-up PR for #24

For now, let me remove the option for angular. As faiss doesn't have the angular option, converting to faiss may cause some problems.
Let's keep the original initialization option for kmeans: minit='points'
If I understand correctly, q @ x.T is fine for IP.
D is not used for DistanceTable
Change the position of minit to the fit function as minit is used only for training
python setup.py install is deprecated. Use pip install . instead.

matsui528 / nanopq