implements configuration class, with unit tests

[ddale]

Unit tests can now be run using python setup.py test

• [x] python setup.py test
• [x] conda build with run_tests.py
• [x] root
• [x] material
• [x] image_series
• [x] image_series:file
• [x] image_series:images
• [x] image_series:omega
• [x] detector
• [x] detector:pixels
• [x] find_orientations
• [x] find_orientations:orientation_maps
• [x] find_orientations:seed_search
• [x] find_orientations:omega
• [x] find_orientations:eta
• [x] find_orientations:clustering
• [x] fit_grains
• [x] fit_grains:tolerance
• [x] find-orientations script uses config
• [x] extract_g_vectors uses config
• [x] fit-grains script uses config
• [x] logging