Add extra words for sentiment analysis

[bristola]

• Add a bunch of positive and negative words and train the model with vocabulary.

• Create program to go through twitter data and classify each tweet to positive or negative, and then add it to the training data.

• Go through a large amount of tweets and add them to the model using program.

• Train model with the data.

[bristola]

Rather than training the model, I need to add a bunch of words to the extra_words file. This will be used to be added to the lexicon for sentiment analysis.