Include package names in setup.py.

This is something you should feel free to tell me isn't a problem except in my imagination.

I have created a virtual environment and then tried to use `pip install . --upgrade` to move the development code into that environment for execution. I was finding that none of the required libraries were making it into the environment's `site-packages` directory and the installed scripts were failing because it couldn't find things.

I fixed this -- on my system -- by adding a list of packages to `setup.py`.

Perhaps, though, I'm misunderstanding or addressing the problem in the wrong way. This is the first time I've looked at the Python packaging system.