Gseapy

This is a major update.

* Fixed a critical bug in NES calculation 105.
* A few minor improvements for a better and cleaner interactive computing experience
* add a new ranking method: genes with absolute value of signal to noise ( `abs_signal_to_noise` or `abs_s2n`)
* change cache directory from `~/.gseapy` to `~/.cache/gseapy`.

* Drop dependency of bs4
* Performance improvement for large dataset: use joblib instead of multiprocessing 92, 70
* Fixed random seeding. Now FDR results are reproducible 95, 70
* Improve heatmap ticks layout

Bump version

Enrichr`` module:

1. Support modEnrich (https://amp.pharm.mssm.edu/modEnrichr/) .
Add `organism` argument. Now, Human, Mouse, Fly, Yeast, Worm, Fish are supported.
2. background argument bug fixed, 66 .
Now, background type could be: list, tuple, set, Series, ndarray, int, a txt file or biomart dataset name.

1. Add new module ``biomart``: Convert gene ids using **BioMart** API
2. Fixed heatmap bug in ``gsea`` output.
3. Support custom gene set input for ``enrichr``. Hypergeometric test using scipy
4. Fixed other small issues

**Highlight**

1. Visualization improvement for `gseaplot`, `barplot`, `dotplot`, `heatmap`. Now these function could be used in python console. see [Examples](https://gseapy.readthedocs.io/en/master/gseapy_example.html#3.-Prerank-example) for details.
2. Leading edge genes now output to the results.