Python-pysap

Added entire docs build flow with examples

See [here](https://github.com/CEA-COSMIC/pysap/pull/170) for release details.

Patch Summary

ModOpt
- ModOpt v1.5.1

Plug-Ins
- PySAP-Astro v0.0.1
- PySAP-MRI v0.3.0

Dependencies
- scipy v1.5.4
- numpy v1.19.5
- matplotlib v3.3.4
- astropy v4.1
- nibabel v3.2.1
- pyqtgraph v0.11.1
- progressbar2 v3.53.1
- modopt v1.5.1
- scikit-learn v0.24.1
- PyWavelets v1.1.1
- pybind11 v2.6.2
- pyqt5 v5.15.4