Refactored reverse_conway.py to separate out ConwayBoard and the Example object ans methods.

* ConwayBoard is now in conway_board.py
* Example renamed to KaggleExample and in kaggle_example.py
* Same separation for tests
* Fixed tests to work with new structure and fixed various bugs created by refactoring
Refactorted classifier.py to separate out each classifier into
it's own file.

* Created ann_classifier.py for neural network classifier
* Created local_classifier.py for local sklearn classifier
* Separated tests into test files for each classifier