FinanceToolkit v1.6.0

I did a new release last week but for everything I've added in it made sense to do another full release. This release includes new models and ESG scores and a lot of the code has been refactored, many new tests have been added and a lot of bug fixes went in. For example, @brianrasmusson noticed in #76 that Apple's data was a bit out of whack. This has now been resolved. I've also added in a lot pretty graphs into the README to show what you can really do with the data, e.g. see this one on the Value of Risk:

It is now possible to view ESG Scores for any range of companies with get_esg_scores:

Next to that, within the Models module, two new models are included. These are Altman Z-Score and Piotroski F-score. The former calculates the chance of bankruptcy based on a set of criteria:

The latter scores the financial strength of the company:

Furthermore, I've added a performance measurement which shows the period growth rate that has occurred (taking out fluctuations over time as shown in the plot below):

Other than that, I've extended the examples and gave more explanation how to add in your own datasets.