Add support for other prediction techniques

[jaARke]

LSTM is just one potential method for forecasting stock price changes. We may want to allow our users to choose from various analysis techniques for some more thorough insight into how a stock's price might change.

To do this, we'll want to add utility functions inside utils/quant/ that perform different types of analysis. Like with LSTM analysis, these functions should accept a stock ticker, data collection timeframe, and prediction timeframe as parameters, and return predictions for each day in the prediction timeframe.

See this issue, regarding LSTM implementation, for a more in-depth description of how analysis functions in general should work.