Data access module

[zmaalick]

Implement a separate data access module i.e. config.py

[nhsavage]

set up a config.py so we can do:

import config
samplepath = config.SAMPLE_DATADIR+'sites_cube_list/'

[nhsavage]

an alternative would be to use git LFS Git Large File Storage (LFS) replaces large files such as audio samples, videos, datasets, and graphics with text pointers inside Git, while storing the file contents on a remote server like GitHub.com https://git-lfs.github.com/

[nhsavage]

I suggest that #5 should just be about the location to store the test data and this ticket addresses the way for the modules to find the data - this might be a config.py or perhaps a config file in ini format which the user sets up and is read with configparser https://docs.python.org/3/library/configparser.html

[nhsavage]

this depends on #5