Tags

* Adds Numba backend
* Refactors One turn feedback module.
* Other minor code clean-up.

Improves blond.test() function to also verify that the required packages meet the minimum requirements.

Bumps minimum supported python version to 3.8 (after matplotlib 3.7 dependency)

Improves plot_impedance function

fixes warnings and some more minor issues

New parabolic distribution function and fixed warning in Plot

Adds test() function to verify proper installation.

Does not compile libblond during installation with pip. If needed, libblond can be compiled manually with the blond/compile.py script.

Adds python-only backend

* Updates README.md
* Simplifies and updates generation of documentation
* minor improvements and fixes

* Minor modifications to include Python 3.6 support

Among others this new tag comes with:
* GPU support with CuPy
* gitlab-ci
* bug fixes, performance improvements

The code has been cleaned-up and released as a package