remove cumulative input argument and use only compound option

[katsu1110]

Issue

Currently when we use qs.reports.<basic or html or full> the cumulative return plot does not look different regardless of the compounded parameter (in the code it is always assumed to be True).

Fix

To be able to get the cumulative return plot without compound, cumulative option is eliminated entirely such that only compound option is used.

[grzesir]

Since this library no longer seems to be maintained, we have created a duplicate of it that we plan to maintain and improve over time. If you'd like to use our version check it out here: https://github.com/Lumiwealth/quantstats_lumi

Please feel free to fork and send your pull request to this new library, we will be actively monitoring the library and approving PRs