v1.2.0

What's Changed

• fix(indicators): preserve OBV on unchanged closes by @JohnDReynolds in #883
• Add missing nbformat>=4.2.0 dependency by @Geochelone666 in #882
• Add ulcer index and Martin ratio to the returns accessor by @anishgurjar in #881
• Fix EWM standard deviation ddof handling by @polakowo in #884
• fix(portfolio): include breakeven trades in expectancy by @JohnDReynolds in #885
• fix(generic): record active drawdowns when a series ends in NaN by @wavebyrd in #886
• fix(base): preserve selected group membership by @JohnDReynolds in #887
• fix(base): preserve unsorted unstack labels by @JohnDReynolds in #888

Full Changelog: v1.1.2...v1.2.0