Distributed Text Vectorizer
    preliminary pass at logic for getting global vocabulary and accumulating sparse vectorization of corpus
Implemented Distributed IDF Computation
wip - simple trie data structure for compressed lookups
wip - refactored simple trie class for readability
wip - defined insert method for simple trie
            refactored constructor and defined __add__
            stubbed __iter__ for later use in __add__
wip - defined remove method for simple trie
            defined __delitem__ and __del__
bugfix - remove method properly halts and removes pointers
wip - implemented begin_with but need to optimize
wip - switched to using in place add and subtract for appending to and trimming simple tries
arranged license notices to be homogenously positioned within each source file
re-wrote distributed tf-idf
wip - experimenting with custom spark accumulators
bugfix: added proper imports to distributed tfidf vectorization
moved tf-idf code into main method
completed distributed tf-idf text vectorization
deleted old and broken text vectorizers