FinanceToolkit v1.8.5

This release contains new Fixed Income metrics as part of the Economics module, these contain Option-Adjusted Spreads, Effective Yields, Total Returns and Yield to Worst. For example, see the Option-Adjusted Spread below (see documentation here):

The Option-Adjusted Spread (OAS) is the spread relative to a risk-free interest rate, usually measured in basis points (bp), that equates the theoretical present value of a series of uncertain cash flows to the market price of a fixed-income investment. The spread is added to the risk-free rate to compensate for the uncertainty of the cash flows. This is usually a better alternative than the usual Z-spread used to price derivatives.

Furthermore, @northern-64bit (maintainer of scikit-multilearn-ng) introduced new AR and MA models that can be utilised with any type of time series. For more information, see #117. @northern-64bit actually introduced many more models in the Finance Toolkit as seen here.

Furthermore, I've introduced bug fixes solving #128 and #129.