Most the changes are bug-fix and performance enhancement.

v<0.8.5>, <12/22/2020> -- Refactor test from sklearn to numpy v<0.8.5>, <12/22/2020> -- Refactor COPOD for consistency v<0.8.5>, <12/22/2020> -- Refactor due to sklearn 0.24 (issue #265) v<0.8.6>, <01/09/2021> -- Improve COF speed (PR #159) v<0.8.6>, <01/10/2021> -- Fix LMDD parameter inconsistenct. v<0.8.6>, <01/12/2021> -- Add option to specify feature names in copod explanation plot (PR #261).