Reichlab Comparison Framework + Backtesting Framework + some other minor stuff

[sansiddh]

A few changes:

• Beta fitting can now be done via gridsearch or bayes_opt
• There is now a script for doing several runs at a time (right now it is overfit to US states, can generalise it later)
• Sets of functions for comparing reichlab models, our fits to gt on the same timeframe
• An updated backtesting framework that works for different CSV outputs and pickle files

Some minor changes:

• A plot that indicates the beta loss wrt time
• Location description for report and plotting has been generalised to all data sources
• Config processing functions changed a bit

[sansiddh]

Also added changes in the following things:

• Earlier forecasting was happening from end of data date, and not end of training date. Fixed that
• Forecasts are plotted for only those compartments on which training is done
• Trial processing is moved to inside middleclass uncertainty
• Generate_report has been changed slightly due to these

[sansiddh]

Updated gitignore such that configs with some number in filename will not be put on git

[sansiddh]

Pruned all old useless csv files in data/data

[sansiddh]

There was a bug such that running the beta fitting cells multiples times through an error. Fixed that.