JOSS review: packaging and organization

[lheagy]

This is related to the installation (issue #7), and should be addressed before then. For python packaging, it is standard install the module as a single module and import packages from there (rather than individually installing each of the python scripts). e.g.

import grain_size_tools as gst
gst.extract_column()

This way there is less chance of name clash, and it is pretty clear what you are importing when.

I will start a pull request to give a few pointers