Added reader_writer.py and __init__.py and made minor changes to the following:

collectionprocessor.py:
- removed try catch block for easier testing

logger.py:
- added _model_changes to comply with flask-sqlalchemy

documentparser.py:
- changed document.sentences to document.all_sentences to match the model
- changed sentence.sentence to sentence.text

sequenceprocessor.py:
- removed comments from index_sequences
I just ran it and there's a couple errors, but at this point I have no idea what's going on with unit tests on my computer so it might be best if you tried it yourself.

On that note, I'm gonna have my laptop at today's meeting so can you help me look at it and figure out why my tests aren't passing when they should be?