TweetParser.csvDataToTrainingData() takes in a buffered reader that contains
tweets and iterates through the reader, one tweet at a time, removing parts
of the tweets that would be bad inputs to MarkovChain (for example, a URL).
This is the class where everything you've worked on thus far comes together!
You can see that we've provided a path to a CSV file full of tweets and the
column from which they can be extracted.